Just to clarify, I killed the owlbear without recruiting any companions. 700xp is due to my Tav NOT 25xp
BG3 doesn't actually split xp between participating party members. Instead, it gives Tav the xp for the encounter, and then all companions (whether they participate or not, I think?) are given matching xp. As the game assumes that you're playing with a full party of 4, you're still effectively getting 1/4 of the encounter xp even if you fight it solo.
Which brings us back to the Owlbear being a total of 100 xp, not 700: see the posts above.
Or to shift the question back to you, why do you think BG3 enemies need to be worth exactly the same xp as in the MM?
