guns

Yeah I also noticed it gives lots of visibility and seating positions to shoot at drones

It would certainly allow faster dismounts (although the idea with this practice in Ukraine isn't so much to get clear, but to be able to actually shoot the drone down, since shooting from a moving vehicle is pretty hard - getting yourself stranded in the middle of nowhere without a vehicle, with a drone team knowing that and itching to finish you off isn't exactly an optimal outcome). Although in practice, I feel like the dismounts aren't actually going to be that much quicker - for one thing, in an open-sided vehicle like this soldiers are probably going to want to be strapped in (see the first few seconds of this video and how much they're bouncing around), so you're still having to undo a seatbelt. You also don't actually have all your equipment on you - you're obviously not going to be taking all those rucks out when you dismount in a hurry, and so if the vehicle gets blown up the "stranded in the middle of nowhere" situation is even worse).

The problem is that this leaves you exposed to... everything else. The media focus on drones in Ukraine has kind of made a lot of people forget that artillery still exists, and actually remains the primary killer - Ukraine causes most of its casualties with drones, but that's not because of how much more effective they are, but just because they don't have enough artillery capability (neither shells nor actual cannons to fire them out of), and drones lend themselves well to highly dispersed manufacture in lots of small workshops (also often hidden in civilian areas...) which are difficult to fully bomb out. One of the main reasons why APCs were adopted in the first place (instead of everyone just continuing to do tank desant, the most "dudes rock" method of transportation) was precisely to provide infantry protection against shrapnel. Even during WW2 itself, we already see a shift from early open-sided half-tracks to the better-armored examples that people usually associate with the term.

And since the Cold War, the risk of troops being struck while on the move, and the depth behind the front at which this can happen, have only massively increased. In fact, already in the late Cold War the US specifically adopted a doctrine built around doing deep strikes on Soviet troops moving to the front (which is what makes it all the more baffling that they're adopting something incredibly vulnerable to a capability they pioneered - you'd think the Americans of all people would be most sensitive to getting taken out like this given they intended to do it to the Soviets).

The technology to do that has only gotten more advanced, and has also proliferated to a point where even much poorer countries can have this capacity to some extent. In a completely open vehicle like this, an artillery shell or bomb doesn't even need to be all that accurate - it can detonate a hundred meters away from you and still shred you with fragments. Cluster munitions make this even worse, and as the Ukraine war has showed the US has no qualms about their use - which opens up the escalation ladder for them being used against the US too. Drones carrying lighter munitions won't have anywhere near as large of a kill radius, but they can still detonate from somewhat further away and thus shorten the interval the troops have to actually dismount. Additionally, one very important aspect of drones people also forget about because of the focus on specifically FPVs is observation - drones actually make artillery even more effective, since they allow enemy troops to be spotted from farther away and to coordinate strikes on them - and since, as mentioned above, these vehicles provide no shrapnel protection, your opponent doesn't even need to use any particularly fancy precision-guided munitions, they could just shoot a bunch of regular old dumb shells in your general area and still shred you.

And finally, there's good old-fashioned ambushes, with guns, which Russian special forces have executed on numerous occasions.