We really should have those games here already.

Why this legal limbo is so hard to be solved?

Depends on which games you mean.

If you mean those made by EA, they no longer have the necessary licenses to sell them. Simple as that.
Game license is currently held by WB. Also, any game that is based on the movies would require EA to buy the movie license again (New Line Cinema). Then there is Battle for Middle Earth 2, which would require EA to also get the book license.

The chances of EA spending a massive amount of money to publish decade+ old games are basically non-existent.

Which Lord of the Rings games? Interplay's? Sierra's? EA's? Warner Bros'?

If you are talking about the older games, good luck convincing a company to make an expensive contract with the Tolkien Estate, just for a straightforward rerelease.

If you are talking about the newer stuff (Warner Bros and others), well, it's not like GOG is a huge priority or anything.

Besides Daedalic's Gollum third person stealther which is all but officially confirmed for release on GoG, Warner maybe might want to make use of the buzz around Amazon's likely dead-on-arrival series and release the "Shadow of Mordor/War" games here in September?

Not sure what the rights situation is for Interplay's TLOTR Vol. I + II (1990 and 1992 resp.), but these would be great to have digitally re-released as well.

Whos is up for LOTR Return to Moria? I think it looks quite innovative at least. Spring 2023 launch from my understanding.