Speaking as a former eBay engineer.

The criticism is that it isn't React, and that nobody uses it but eBay.

There's nothing really wrong with it other than that there's no reason for it to exist when other frameworks work fine and have community traction. There's nothing special about eBay that requires it's own special UI framework.

And when we hire contractors to do anything they won't touch Marko so we have to use React anyway on a lot of projects.

Just not an efficient way to spend the companys money creating and maintaining a superfluous framework nobody asked for.

Get better contractors. It is just a JS framework. I have had to work in various weird frameworks, backend and frontend, and it is easy to get started in an existing codebase. Most of the fundamentals are the same.

I am so tired of developers who are scared of learning new things.

> And when we hire contractors to do anything they won't touch Marko

What's the point of hiring contractors if they will show zero flexibility to work with your existing stack?

A consultant could make you reevaluate your stack (and that would be the point) but IMHO contractors should just focus on getting the job done.

SEO and CWV are not good enough reasons?

Ebay is not your mom and pop e-commerce website.

If Ebay had used React the business would have suffered. That's why Amazon isn't using it either.

React is more of a library, if you want to compare Marko to something you could take Svelte, Next or Qwik. That said, React seems to be moving in the same direction with React Server Components (announced two years ago and still not available).

I think the main criticism is portability of skills, ie everyone wishes ebay would just use react.

This is why engineers shouldn't pick tools. They prioritize their resume over the quality of the product.

Most of them anyway ;)

Which in my book is a fairly weak objection. Learning a new framework does not take much time if you already know one framework and you are put to work on an existing code base. I only knew Vue when I started working on an Angular codebase and it only took me a couple of days to get up to speed.