Some salts being “saltier” is mostly not true.

If used as a garnish, course or flaky salts take longer to dissolve into your saliva, so the salt flavor isn’t as profound. But if it’s cooked into the dish, there’s no difference. Everything is already dissolved, so equal masses of salt produce equal results.

There’s a little to be said for “mineral salts” where there are trace elements besides NaCl. But that path leads into pseudoscience pretty quickly.