3.x and 2e∆ versions of that were passive.it happen because of where everyone was in relation to each other how they were facing and sometimes because the one taking turn was about to do something that gave one of the others a chance to be sticky with an AoO due to movement or spellcasting.. god wizard-esq control/debuff spells might add some creature & #x# zone specific stuff, but intended to be stuff that lasted most of the combat and was fairly staticI wasn’t aware that terrain, movement and positioning had been absent from any edition of the game.
Also, BG3.
The 4e versions were heavily leaning on short lived/mobile & often highly localized effects that pop in about of being round by round. The 5e version is almost exclusively leaning on it due to efforts to streamline and simplify awAy the tactical grid elements to specific powers actions or entirely.
A computer can easily track that kind of chaos. Human's forget and argue over "wait a minute, I put a miniature sun on that one so xyz should have modified that thing that just happened. Then you have the 3 stooges style square dancing with spirit guardians and such
∆ most of it was added later in player options: combat & tactics.

