I've done my own digging on free dating apps for serious relationships for the 40+ and come up short. The crowd relationships case is instructive — the quality of the filters collapses as soon as the platform caps how many searches you run a day. I judge crowd relationships on one thing: the platform buries the cancellation flow, so it pays to ask a specific question in the first message.
If crowd is your priority, the proportion of dormant accounts is the number worth watching, not the price tag. Look closely at crowd apps and you get further if you check what the free tier gates before investing time.
For crowd relationships in particular, the platform resets your filters after an update, which explains most of the complaints in threads like this. When it comes to free dating apps for serious relationships for the 40+, it is worth checking the proportion of dormant accounts before you look at raw member count. If you have been through the crowd version of this, I would rather hear the unglamorous account.