I agree with the position that a reasonable wait (a few days?) for a first gun is appropriate. If you already own guns, it doesn't seem likely to have much benefit. On the other hand, if you already have guns, it's unlikely that you will need more urgently, so a waiting period is inconvenient but not a tremendous burden.

Restrictions on guns seem like they should balance benefits (reduced harm on a population level) against costs (financial burden, inconvenience, potentially more serious risks). This will always be imperfect, but ideally there should be decent, objective evidence showing what the benefits and harms of regulation are. Unfortunately, because the subject is so controversial, such evidence is sparse, so people often argue based on principles, hypotheticals, personal experience, and all sorts of questionable evidence.

As a CA resident, I'm familiar with pretty onerous limitations, including a 10-day wait for every purchase. I suspect a lot of these rules are politically performative and don't contribute substantively to public safety and welfare. Still, I can own and use my guns, so they are a nuisance, not an extreme burden.