By wins in Florida and Illinois, Trump CLINCHES Republican nomination, Biden likely the Dem nomination, Should we CANCEL other primaries ?

No in a Democracy you still have to let people have a say even if won't change the final results. 

Get ready for 2016 deja-vu. Still a lot of Bernie or bust folks out there. They will lose their minds if Bernie isn't allowed to go all the way to the convention and even if Biden is short one delegate from the 1991 delegate requirement, they will blame superdelegates for putting Biden over the top. It is a problem for democrats. These supporters will flake off, yes, some will go with Biden at the general, but others will stay home or vote third party. Because they would rather 4 more years of Trump than admit they lost the primary.

Well sure....................

For the sake of all our health, Bernie Sanders should drop out of the race so we can name Biden as our nominee and pledge all remaining delegates to him so we will no longer have to hold crowded primaries which are now a health risk due to the coronavirus.

Until Biden clinches, Bernie would object, and rightly so.