> Not a lot of good solutions.
There are a lot of easy improvements; there's no perfect solution, but this is a perfect is the enemy of the good situation.
> Can't let everyone in.
There are two halves of this:
Not everyone is personally acceptable as an immigrant; there are reasons for prohibition based on individual history.
You can't let everyone who isn't individually prohibited in for free because assimilating immigrants has costs.
The US has a basically reasonable approach (perhaps wanting some tweaks in details) for the first, but less than ideal handling of the second; most notably, aside from issues with the design of some of the available visa categories like H-1B, hard per-category caps and even moreso, per-country caps on visa categories exacerbate supply/demand imbalances for which the natural consequence is illegal migration.
> No one cares for merit based immigration like other countries
US preference categories, which are the basis of virtually all legal immigration, are merit-based, though you may not like then particular notion of merit on which they are based.
> and no one wants quotas
We have both per-category, and within each category per-country, quotas, and lots of people want them (and many want them to be smaller.) It's not a good policy, but many people absolutely do.want them.
> because it'll clamp down on immigration from countries with large populations (China and India).
Well, the particular formula effects countries with large number of people qualified and seeking to immigrate, which depending on the Visa category includes Mexico, the Phillipines, China, and India (and I think a couple others in a few categories.) Population has an indirect role, but it's not the direct driver of quota imbalance.