As for the long term effects, I do notice misspellings whether i want to or not. Sometimes it happens with syntax errors in code, too.
Never had any interest in spelling bees but I've done a huge amount of copyediting/editing so I'm very aware of mistakes (including misspellings) in writing generally.
As a sibling pointed out, what the spellcheck accepts is law, and those dictionaries have grown signifigantly.
It's been common forever, because “payed” follows the most common pattern of forming a past participle in English (“ad ‘-ed’”) and also fits the pronunciation people are familiar with from oral communication; it's been infecting more formal communication since automated spellchecking displaced much second-eye proofreading because it is actually a correct spelling of that verb form for certain—though less commonly encountered—meanings of “pay” (yes, the verb had different conjugations with the same pronunciation and different spelling for it's different meanings because English is just that way.)
https://www.merriam-webster.com/words-at-play/hung-or-hanged