Destiny is MMORPG-lite. That's​ not a bad thing at all (in fact it's part of the appeal for me), but it does mean that the class differences are minor and while certain skills are convenient in certain situations, none are essential for any PvE content. PvP is pure twitch with occasional "free cheese killz!" moments (with only Defender really lacking). I sometimes think I'd like Destiny to be closer to a traditional tank/healer/dps game but then I recall all the time spent in lobby spamming "LF Healz" and am cured of it.