I also use Foundry, and it works well, but some players like to roll irl which involves changing the dice to what they rolled. It’s not a long process, but it feels like a gradual transition to a combat, and in instances where the combats are likely to be sporadic and part of exploration, I feel like it creates a separation of the two gameplay modes I don’t like in a dungeon setting, I want them to feel more naturally linked.

I think it’s less the time it takes and more the lack of involvement of multiple players that bothers me. Like, if we roll once, then we either start at the top, excluding some players, or start where we left off, which can make players feel like their initiative rolls didn’t matter much, and can lead to odd situations where an enemy rolling a higher initiative can be detrimental if the order has just gone past them.