AAA games budgets get way more expensive evey new generation.
This generation, with new AAA games going above $300M, and considering Sony gets on average aprox. around $34 or less per copy sold they should sell over 9-10M copies to be profitable.
It means big AAA SP console exclusive games with the sales scale of Bloodborne, Death Stranding, Dreams or Days Gone wouldn't be profitable.
Meaning, if Sony would have continue locked to SP games exclusive to their console would have needed to stop making big AAA games outside their super seller IPs like GoW, Horizon, TLOU, Uncharted, Gran Turismo, Uncharted and Spider-Man.
Having PC and GaaS increases the revenue and profitability that their 1st party games have. Which keeps them less pressure on the profitability of the projects.
GaaS and PC have absolutely no negative effect to PlayStation: its active userbase keeps breaking all time records, its software revenue keeps breaking all time records, its game sub revenue keeps breaking all time records and their console only releases keep breaking all time records (and particularly with sequels of games ported to PC). So if there is any effect of Sony's GaaS and PC strategy on PS is positive.