Anything I recommend around Plenty of Fish has to clear one bar, which is how aggressively it pushes credits at you.
I gave Plenty of Fish about 4 weeks before I formed a view, mostly watching what the free ceiling looks like in practice.
If you can only manage a few evenings a week, how far the free tier actually stretches matters more than raw volume on the site.
Before committing time to Plenty of Fish, work out whether messaging costs anything once you start.
Take that as one data point on Plenty of Fish rather than a verdict.