The problem is that once a standard is set, it's set. Time and time again third parties will follow suit. We thought they wouldn't do it at 59.99, they did. Same with 69.99 and now potentially 79.99. They will use the excuse of 'we'll charge you through MTX', but given the first chance of 79.99 sticking and actually garnering sales, they'll quickly sweep that talking point under the rug while keeping it in the game anyway.
Hell, most companies have already convinced everyone that games should cost as much as a physical edition (with media, booklet, and case) on day one even when you buy it digitally.
All of these things are a slippery slope we have already witnessed, so I don't see why it would suddenly change unless people truly don't buy the next GTA, Mario Kart, etc. and they bomb in sales, forcing a discount. Considering that people will pay upwards of 150 to play GTA 6 tomorrow, I don't see this happening.