I have played and completed every single mainline Pokemon game and PLA is the first game I actually felt tempted to "catch them all".
In every Pokemon game I played I basically ignored every Pokemon that I didn't at least somewhat plan to be in my main team, and every Pokemon I caught or ended up being rejected I released into the wild because I think having them stuck in boxes is cruel.
In PLA I've been playing for almost 56 hours and I've only just made it to Cobalt Coastlands because I've been spending my time getting as many dex entries as possible. I still release every single Pokemon I don't plan on being in my main team (so far the only Pokemon that fit that category or Hyphlosion and Scizor) but never have I been so focused on actually catching Pokemon.
Also this game is dangerously addictive.