I was a preliminary-level skater as a kid and now as a middle-aged adult I'm stronger in my basic skating but will probably never land my lutz and axel again, much less ever master the beginning doubles I worked on as a teen and for a while in my late 30s.
When I was in grad school, I had a flexible daytime schedule and access to one or two adult-oriented dance or general skating sessions at times, as well as regular freestyle sessions.
Now I work full-time so daytime sessions are not convenient although I can take an extra hour for lunch once a week -- on relatively empty public sessions, "private lesson ice" when offered and when I can schedule a lesson, freestyle sessions when offered, or dance sessions that attract older adults and those with flexible schedules (but on which I can't practice freestyle skills, nor patch -- MITF or dance patterns and isolated skating skills only).
Otherwise I tend to skate on regular evening and weekend freestyle sessions that are popular with all ages and skill levels, and sometimes early mornings.
If there are no more than 5-10 skaters on the ice it really doesn't matter much what the others are doing or how old they are if most are around my skill level or below.
If there are 20-30 skaters on the ice, if I'm practicing freestyle then it's best if everyone else is too. If I'm practicing moves, it's best if the other skaters recognize the patterns.
If I'm feeling aggressive and wanting to put out my best skatin, the ideal situation would be no more than 15 other skaters of my level and above, including a few high-level competitors. You rise to the level of the session.
If I'm feeling tentative, e.g., if I'm out of shape for health reasons or having been off the ice for a while, then I prefer a slower paced session to get my skating legs back under me.