BG and BG2 were 2e, as was IWD. IWD2 was 3e, as was NWN. ToEE was 3.5, as is the upcoming Realms Beyond. BG3 and Solasta are the first games using 5e.
You forgot NwN2, also 3.5e.
Realms Beyond and Solasta use the D20 SRD but do NOT use D&D settings or lore. So for me they're not *true* D&D games.
Would you say that about any D&D game that doesn't use an officially licensed setting? like .. 80% of games and campaigns made by players for their own tables?
And no, I didn't forget NwN2. But we all ought to.
