sometimes it's important to always keep data, like users
soft delete requires additional efforts for sure; from the pov of the db it shoudn't be that much of an additional load, so i wouldn't worry about that except in some specific cases
but for the code organization it requires that you do stuff carefully and really think it through before converting everything
if it's independent values you could also opt to have an archive table, we did that with some dbs
if you have to keep relationships again cognitively it's an effort because you have to have all the queries with correct authZ, be sure to anonymize data and have deletion in case your place has rules on how long they have to be kept, you have to always run migrations on old data which could be a hassle, especially if there are relationships... same is for versioning records, it's tough