Any way to not use IMPORT

While it's true that other RAW converters allow files to be accessed and processed by reference to the file system, it's not actually a better (or worse, for that matter) way to approach the task: but to benefit from everything Lr can do for you, importing is simply part of the price of entry.

It really just needs a little attitude shift on the part of the user, and it stops becoming a burden, just another way to do things - and it does confer benefits, if you want to maximise Lr's capabilities.

If you're not persuaded of those advantages, then - as Rob said - you'll need to look elsewhere.

Use Bridge and Camera Raw.

Are you talking about Lightroom Classic? You don't say.

Photos must be imported into Lightroom Classic before you can work with them in Lightroom CLassic. You can import the photos so that they stay in whatever folder they are in now, in which case you would import using the ADD option.

If your Lightroom Classic Creative Cloud Plan includes Photoshop, then files can be opened directly into Camera Raw. You should also check if you're Classic Creative Cloud Plan gives you access to Adobe Bridge. Bridge has many of the features found in the Library module of LrC without the need to import your files, and can open them into Camera Raw. 

" any way not to use import" Yes. Do not use Lightroom-Classic. 

Being very facetious I know, but the 'Import to a Catalog' is the only way LrC can be used.

CATALOGS- HOW THEY WORK

And you do NOT have to Import EVERY photo on your hard-drive. You can be selective, but that is defeating the useful database functions of the Catalog to reference all you photos with keywords, Collections, Ratings, etc,