Virtualization aside, we haven't abandoned basic infrastructure, but centralized it in the hands of a few huge, expert providers. IMO this is a good thing, and was both necessary and natural as the Web grew to offer more and more opportunities to more new professionals. In detaching HTML from HTTP from ARP, etc. we gave rise to entire new professions like full-time UX (which arguably the Old Guard was never good at beyond a small audience of academics and engineers), or various flavors of front-end developer, or serverless ecosystems.
The Web and associated technologies advanced so quickly it was impractical for a single IT or network department to know all of it anymore, and some of the newer webapps wouldn't have been possible if that same team or company had to also manage all of their own basic infrastructure like it was the 90s still.
Now you can be a front-end only shop, or a UX consultant, or a network engineer who never has to touch HTML, or, or, or... maybe big enterprises always had and could always have all of those in-house, but the division of labor has been a huge boon for small businesses and startups and nonprofits, who just don't have the same resources.
As someone who grew up configuring zmodem and running BBSes and having to (mis)configure NetBIOS all the time, I am so, so glad I never have to worry about OSI layers and such ever again. It's boring to me, and the experts at it are SO much better at it, might as well let them handle it. Especially when the cost of that outsourcing is often like <$100/mo. Well worth both the time and money... and sanity. The division of concerns lets you focus on the things you're either interested in and/or good at.
Our professionals haven't gotten worse. The stack has gotten much deeper.