Just to add my own two cents (from a f2p perspective, at least): This game is not for everyone. If you're bored and have a few hours to kill, you're not going to say "oh let's play FKG for a while". It's a background game, you leave it running in another tab/window while doing other stuff. The fun/satisfaction gained from it is from getting a larger and larger roster, leveling and evolving and, er, "affection-ing" the ones you do have, and the occasional "omgwtf" shiny from a gacha.

These are all more long-term goals, so you need a certain amount of patience to enjoy them. If not, then there's nothing wrong with that. It's your free time; you should spend it doing stuff you want to do.

That being said though... Specifically on the topic of flower gems, I actually thought the same for a while. When I first started (a few months back), I was drowning in all the flower gems, but then quickly (as you have) hit the point where they start to dry up. And I thought "well I guess I won't be using gems much". Now, though...

* New event every 2 weeks, each with 16 gems, or 8 a week.
* Reissued event every 2 weeks, each with 2 gems, or 1 a week.
* Approximately 2 flower gems per week from the login (ignoring the login cards with nothing but gems).

That's 50 gems every 4-5 weeks, 100% guaranteed, once your teams are strong enough to 3-medal the event 80 maps. Factor in the occasional affection flower gems, the nothing-but-gem login cards, and the odd reward of gems from gathering or whatever, and you can do a 10+1 pull once a month on average.

So if you decide to stay, that needs to be your mindset. You've hit the point where you need to buckle down and get stronger teams, pump up your helper squad to get better friend requests, max out your best five-star (because if I recall that affects how powerful the friend teams are), and getting into the routine of trying to clear (if not medal) the event maps. You've passed the "easy at the start" hook. It's a bit of a hump to get over, before things start getting easier again, but it's more than possible.