First off, stuff that works well on the tabletop doesn't necessarily work well here. Reactions are a prime example. On the tabletop, you're playing one PC with one Reaction per round and it's likely you get 0 to 2 potential triggers for it each round, and you naturally decide whether to trigger it and so on. In a game, with a 6 person party, each of whom has a Reaction, if you go turn-based and replicate 5E, this would mean you'd very often have "trigger Reaction Y/N?" pop ups between your turns. Some turns you might have an awful lot of them. Sure you can only say yes once, but if you're aiming to use a Reaction in a specific way that might mean clicking through a lot of Nos.
XCom doesn't have this issue as it is a purpose designed turn-based computer game, and reactions are triggered automatically to avoid breaking the flow.