Look at it from the other side for a moment, consider what you’re asking.
Hosting companies offer lower tier packages with the most popular plugins because they’re an easy sell, and consistency across thousands of client instances lowers support costs. They aren’t creating each instance by hand, automation takes care of everything.
The functionality you’re referring to above isn’t even a plugin, Log in with Google and Facebook Login are standard features of core, and have been for years, because they’re both so widely used.
Then consider the OpenID plugin which was first published about ~15 months ago. It wouldn’t make sense to arbitrarily install into tens of thousands of environments, because only a minute fraction of customers will utilise it. Doing so would complicate those installations, and cause each install to use fractionally more resources, increasing the support and operating costs for that tier of service.
Nobody is making you pay more to use an open standard, that’s a dramatic misrepresentation of the situation. Nobody is making you pay anything here, anyone is free to follow the Standard Installation on a $5 DigitalOcean droplet and install the plugin yourself. The uplift in cost is to cater for more complexity, more resources and the associated higher support costs of both.
This is the crux of the problem, OpenID is still ‘small’ compared to more recognizable providers. You want OpenID to be treated as top tier, because it helps the strategy of your employer, but doing so prematurely undermines the strategy of every hosting provider out there.
You do have a choice in this situation, if you think a lower end hosting package with OpenID as standard is a compelling option then why not offer to host it yourselves?
Conversely, if you don’t want to, why would you expect anyone else?
p.s. I’ve worked with education customers in the UK for about ~12 years now. OpenID popped up on our radar in 2014 and I’ve seen some sites use it to huge success. I still wouldn’t advocate for it to be integrated into smaller communities, because it just doesn’t suit those groups. Maybe did.app can change that, but expecting providers to roll out the red carpet isn’t going to get you any close to that particular goal.