If they loved rpgs as much as you, they'd find a way

Having run and participated in a few multi-year games with busy adults with children, my absolutely unsolicited advice for anyone wondering how to do the same is the following:
Run the game online. I still like in-person better but you cannot underestimate how much logistical burden is removed by allowing folks to log in and jump on mic/video. I recommend FoundrtVTT - no subscription and it has support for a ton of different systems, particular shout out for the masterpiece that is it's PF2e support.
Get more players. This seems counter-intuitive since that is more points of scheduling conflict. However, what you do if you want to run a 4-person game is get like 6 players. If at least 3 or 4 can make it, have the game. The PCs whose players can't make it just fade into the background and can reappear next session. Sounds weird but it keeps things moving. You'll get a feel for balancing encounters based on who shows up the most and will get better at that.
Run shorter sessions. I feel like I see a lot of posts about people running 4+ hour sessions and when we do get in person, we do that. But for week-to-week games, that is a significant commitment. I know for our group we keep them 7:30pm-10pm with some understanding that the first 15 minutes is usually time spent letting delayed people show up and going over what happened last time (good opportunity to give out inspiration/hero points). A rushed hour-and-half session is still better than a canceled session.
Talk to your players. I think this supercedes the above but just chat with people to see what can work. I mentioned our start time of 7:30 but if people are not able to start that early, we'll postpone to 8 or even 8:30 that night. That comes from communication. Check in with each other periodically to see if there should be other times considered. Essentially, focus on what works for your table. Be flexible, allow folks to miss a bunch of games consecutively if needed. Make sure it's a fun thing and not an obligation.
All that being said, if people aren't engaged in the game or that interested in playing, there's not really anything you can or should do about that aside from find other players.
- Another benefit to remote Foundry games: you can stop at any time and the board/scene does not change. Hit a hard stop time in the middle of combat? Who cares! The turn tracker will stay right where it’s at until next week.
  
  It is truly a blessing for the times I torture my players with a 4 hour boss fight which was, of course, preceded by 1.5 hours of them being indecisive at the magic shop.
- Hey! Couple q's regarding Foundry. I'm the DM of our group, and have a ton (and I mean a ton) of homebrew for the campaign we're running atm. The homebrew spans changes to core mechanics (no damage rolls for example) to completely revamped classes, races, and backgrounds. How easy is it to homebrew on foundry? I've been eyeing it for a while because roll20 is so user unfriendly I was thinking of going back to Owlbear and manage everything through google sheets, or upgrading to paid VTTs.
  
  I’ve been running games on foundry for 2-3 years and don’t think you’ll have issues with custom classes, races, or backgrounds unless you are doing something really really wild.
  The core mechanical changes are going to be harder, but compared to roll20 it wouldn’t even be a competition foundry is just better for customization.
  The most annoying thing is probably going to be porting all your homebrew. You can share it between worlds though via compendiums which is a nice timesaver.
- Superb advice!

In my experience, the winter months kill many a game. Between the holidays, work stress, weather, and seasonal depression it can be hard to keep your group together for a few months.
My players love our game, so I'd be hesitant to say that it's not important enough to them. Sometimes we let the important things slip when we're busy, or a perfect storm just keeps you apart.
All that to say, we usually get back together in the spring. Sometimes there's attrition, and usually we're playing a different game when we come back. But that's okay too, it feels natural to start up something new after you've lost your momentum

It absolutely was scheduling for us.
We loved the game and have been playing a pretty long campaign for slightly less than a year.
Then work got in the way for a few members, me included, and we weren't able to find a day when everyone could play for a few hours consecutively, with some of us working on the weekend, others on the weekdays, and others still having life-changing events going on, such as having to move hundreds of kilometres away.
We still manage to play once in a while, but nowhere near the weekly cadence we had before.

It's really hard to organize 7 people tbh. It hasn't killed us yet though, almost a year in

That's essentially the same thing, right? The rest of their schedule was more important, so they prioritized that.
- Well technically yes, but the game can still be really important to you, while not being as important as working at your job that you need to survive or something. I envy people who have the flexibility to be able to completely prioritize gaming with friends, but unfortunately that's not the case for everyone. I miss my old D&D group :/

One of my fondest experiences of D&D is a campaign that ran slightly over three years! Not everyone we started with made it to the end, but the folks who did will forever hold a special place in my memories.

I rebooted my game recently and made the players promise to commit to at least one game per calendar month, which we schedule immediately after playing. Players who weren't willing or able to make/keep that commitment were dropped and replaced and now I have a pretty good thing going on. There's more people who want to play than want to GM, so if you're GMing you can afford to filter out uninterested players.

You know, in the end, not every band is Rush.

Sometimes yeah. But also I don't expect them to care more about D&D than, say, their kids, their careers, their financial wellbeing, etc.