🎸 Guitar question: Is memorizing and practicing scales a good use of time if I don't plan to improvise? Thanks!?

Here's an analogy: "I want to be a stage actor and not a playwright. Do I need to understand grammar, sentence structure, punctuation and vocabulary?"

As a practical matter, I would recommend learning one scale at a time up and down the fretboard. (Scales you would likely be playing for your chosen music) The big benefit is hearing how notes sound in relation to each other/learning intervals. Just learning a scale for the scale's sake, in my opinion, is of limited practical use.

I am a multidegreed full time classical musician. Made every penny in music, music education, music instruction since 1973 . I play 60 scales (15 majors, 45 minors) and their arpeggios and scales in thirds, in a rotating pattern over 3 days - and I use a spinner I made to ensure I hit then all in a rotation cycle of 12 different articulations and/or phrasing, over the full range of the flute. Do the math - sixteenths@120, so this takes a WHOPPING . . . . less than 10 minutes a day. This is my warmup. Or really a section of it. Then I get to work on music. So you decide - wanna be a whiner or a winner? Career or regrets? I tell all my students - hard work beats lazy talent, 7 days a week. This morning my husband was up, shaved, showered, dressed, we ate breakfast- and he was seriously at the piano by 7:20. I was in my jammies, reading the funnies. Got to music work a little later - he was choosing literature for our next concert. How bad do YOU want to be a fine musician?

That's a good thing to do for any instrument, guitar included.

I always warm up to scales

Yes, that is important., even if you were to want to improvise. If you don't know the fretboard and are unable to play scales in all positions, you will be a very limited player.

if you want to be a good guitar player, yes they are a good use