Wireguard is a great VPN protocol. At this point in time it is a lousy VPN solution for all but the most basic uses. Given time the necessary infrastructure to make it a great VPN solution will develop.
What's a common-case VPN problem, the kind that (say) 3 out of 5 company or personal VPN users would have, that aren't well addressed by Wireguard, other than lack of Windows support?
My two cents... (with my only experience being installing Wireguard on a RPi to get a VPN connection back to my home).
I think the biggest problem is the lack of a simple GUI process to manage the connection.
I have scripts setup to run `wg-quick up` or down hanging out in my menubar (Mac), but that's not something that I'd expect everyone to be able to do or setup themselves. However, a "Enterprise" managed environment might be able to come up with something that works. This is something that the community could fix independently.
However, (at least for Macs) the install process requires installing Homebrew, installing a package at the command line, editing a config file with strange keys, etc... This could all be GUI-fied and made less intimidating.
But, the other (probably bigger) thing for corporate use is having a company behind the protocol to be able to buy products, support contracts, etc... I mean, a company isn't going to switch from an SSL VPN to Wireguard if you can't have an outside entity to sue if things go wrong. This is something that will just take time to build up the comfort and scale.