I've got mixed feelings on this one.
They can make a server feel more full when there aren't many players on, but what if player counts were healthier? I think the real answer is they create more issues then they solve. We need a good solid BF game, meaning: Well balanced, good hit reg, well optimized, fully featured, and a single title they work on for several years. Which in a lot of ways BF2042 does some of that pretty well. It is optimized Now, it's pretty much fully featured at this point (still a couple things missing). The hit reg is awful, and I think Crossplay has a lot to do with that. The balancing is atrocious in one way or another. Vaulting still isn't done correctly. There's a lot of little things that add up to chip away at you and make the game annoying after a few long play sessions. Back to the topic...
You can count on them to give you ammo, which is nice. Most people don't drop ammo, or when they do, it's in a choke or out of cover.
They take over my MF'ing Bolte and are the absolute worst drivers of any AI ever created! They SHOULD NOT be able to drive vehicles.
I think they should be limited. Maybe there should designated spots for them? What if each team had a couple squads of AI on their team, and their sole purpose was to rez, heal, and drop ammo? There's some interesting things that could be done with them. I'm not in love with the current iteration of them, but there's moments when I see them working okay.