IMO it depends, did you find the warp zones yourself or were you told about them? They're hidden. Finding them by luck doesn't feel like cheating to me, but getting outside knowledge to bypass big parts of the game kind of does.

In speedrunning circles there are categories like 100%, any% (get to the end in any way), minimum percent (get to the end doing the least possible), glitchless, no major glitches, etc.

People have different interests and finish in their own way.

If you’re really into a game you’re missing out if you don’t try to beat it in different ways.

If you’re really into one particular way you’re really kind of being a bad sport if you insist others enjoy a game in your preferred way.

Not in this context.

If you told me you beat Mario on NES but you didn't even play 24 out of the 32 levels, and you never beat them otherwise, I don't think I'd give you the same credit as someone who beat each level.

This is why Any% speedruns (get to end credits any way possible) are their own category.