Free to Play games are basically a test of willpower. They use every trick in the book to get people to keep playing and spend money. FOMO via time limited events, gambling addiction via loot boxes/gacha, impatience via playtime or realtime limited resources, sunk cost via slow and difficult to earn resources/rewards. All of which can be “solved” with money.
On the other hand if you’ve got the willpower to just… ignore FOMO, ignore the gambling, and just walk away when you’ve played a little bit each day, F2P games actually offer incredible amounts of content. Over the past decade I’ve played about 5 different F2P games and never spent a single cent. Each one was pretty fun, and I just walked away when I got bored.