As per title, this annoying phenomenon is still occurring.

What seems to happen is this:

When most of the team is dead and an objective then gets capped by one or two surviving players; the dead then respawn some distance behind while the "race leaders" sprint off to the next objective as fast as possible. While the racers are doing this, the respawned players are still scouting around for other weapons on the ground that are better than the broomstick and pea shooter they spawned with (the racers, probably, have their own loadout in tact). This further opens up the distance between them and the racers.

What can be done about this? Just vote kick them?

I think the best thing to do is, remove the mosin and tarkov pistol given to people that respawn, as this causes serious frustration, I'll prefer increasing bot difficulty or a system that reduces ur supply points everytime u die

It's the attitude of some players and won't be rectified any time soon. It's not due to the Nagant/Pistol loadout upon death, it's the problem of people playing the game like COD or CS:GO.
I find that the game(Especially Hardcore) works best when people are playing as cohesive groups, which is very hard to find. Imo there really isn't a way to stop it, a lot of players think that being the hero is most important rather than actual team gameplay.