Everyone does them at their own pace. Some do replies really fast, others take about a week. It's better to let people reply at their pace than to rush them. A reply with time being taken to be done well is better than a rushed reply, always. Also there are some people who will announce when they'll do replies, but not actually do them and some who have a priority list of who they'll reply to first. Both are not good. IF the priority was oldest to newest rp, then it is fine as doing it like that also more easily helps you keep track of who you replied to much more easily especially if you're on mobile as often as I am for example. If you are one of those people who make statuses where you say you're getting to replies, that gives people the notion that you're doing your replies and as such if a day or more passes and they ask about their reply, you lose the ability to complain about them asking about their asking about it especially as some people will say they're getting to them, but not reply to people outside their circle of friends despite saying they're getting to rps more than 3 times in a week and get called out IN PRIVATE about the lack of replies. If for example, lars alexandersson has 25 replies to do, but he KNOWS he can't get to all in a day, he'll at least give a heads up after announcing getting to replies to those who are waiting and may be expecting a reply that day and be like.
"kay, I can't get to all of these in one day, so... I'm replying to Ebon, Virgil hawkins, Faye morgana, Edward Elric,Testament, Anji, and Artoria pendragon (ruler) today and tomorrow Justice, Date masamune, A.B.A, Chachamaru, Red Death, Raiden, and Kliff."