For some of them I kind of lost access so I would need to write emails to instagram or whatever, for others I would need to remember and to access to each one of them and delete them.
The hardest would be gmail with people having my contacts from like 10 years ago…
I get where this take is coming from, but I’m not sure I agree.
Some social media sites already block new users from using the usernames of deleted users, for just this reason.
And scammers don’t need to copy your username to impersonate you. They just look at your public social media accounts, scrape a bunch of data about you online, and create a new account with a similar name. Then they message your contacts and say “hey, my account got hacked, this is my new account, here’s some personal information so you know it’s me, and also can you send me $500 by iTunes gift card so I can make rent?”. Happens on Facebook all the time.
If you delete your social media account, the social media company still has your data (and probably many many backups of previous versions of your data) and can do whatever they want with it, but, scammers and data aggregators and surveillance agencies without access to that company’s internal data will have more trouble finding it. If you leave your social media account active, though, it’s still accessible to those third parties, and the data on it can help them build their a profile on you.
In other words, deleting your account makes you safer.
On the other hand, it does depend on what data you put on the account in the first place and what data miners can get out of it - in OP’s case, if their Instagram account only has a couple of landscape photos from ten years ago, it probably isn’t worth the effort to reactivate and delete - if it has a ton of person and location tagged photos that could trace where OP was and who they were with for a significant length of time, I’d wipe it.
A reasonable argument and I agree that impersonation is still possible without the scammer taking the excact username but it’ll still be easier to fool your contacts when you don’t have an active account.
For example consider two worlds - in one you have an instagram account, in the other you don’t. The world in which you have the account, people who only know you through that account and don’t use other platforms where you’re on, are less likely to fall victim to scams because they can always verify that the scammers account isn’t your account. In the other world this isn’t possible and thus it is more likely people who don’t know you directly will believe the scammer.
Also my point on the cost of the account still stands. I do admit that having an open account which gets scraped is an issue but if you have a “private” account, most of the 3rd parties lose access to it’s content. Although I’m sure three letter agencies and meta have a custom API which can query all accounts, public or private, the point you’re trying to make is moot, as if we’re talking about opsec, if you already have an (insta) account, all it’s data is logged somewhere and it likely won’t be deleted in the near future.