This looks a bit dry. Also people who don't mix the sauce with the pasta in the pan (and a little pastawater) before serving, have no idea to what levels of flavour pasta dishes are capable of reaching.
For the record, the starch in the pasta water acts as an emulsifier- things like carbonara rely on it to keep the sauce from breaking; and it’ll help red sauces to adhere more to the pasta.
As a side note… cook the pasta little under and transfer it to the sauce to finish. (I believe that’s what the other commenter was suggesting,)
Usually I just do a terrible job draining and that’s enough- it doesn’t take a lot;
I separate the sauce and pasta for a different reason: I cook a large batch and will always have leftovers, so keeping them separated prevents them from spoiling faster (even when refrigerated). An already-mixed spaghetti also gets dry in the fridge compared to heating them separately later on.
Heating them together is usually fine in my experience, but storing them separately is a must. The pasta robs moisture form everything else, getting mushy and leaving the sauce dry.
If you really want one container to bring leftovers to work, put the sauce on the bottom add a layer of cheese, then put the pasta on top. Don't mix everything until it is warm. You can get surprisingly ok results this way.