What's concerning is the 6-month window. Supply chain attacks are difficult to detect because the malicious code runs with full user permissions from a "trusted" source. Most endpoint protection isn't designed to flag software from a legitimate publisher's update infrastructure.
For organizations, this argues for staged rollouts and network monitoring for unexpected outbound connections from common applications. For individuals, package managers with cryptographic verification at least add another barrier - though obviously not bulletproof either.
The crappy installation and update channels are often tightly integrated with the vendors' monetization strategies, so there's a huge amount of inertia.
Microsoft Store could have changed this situation, had it been better designed and better received. Unfortunately, nobody seems to use it unless they have no other choice.
WinGet looks much better, but so far it's only for developers and power users.
I can't say it would have guaranteed people would have liked it, just that those were needed for it to have a chance.