This is valid, but it assumes that there is a specific issue that needs to be addressed. Someone who naturally has ok time but races fills or adlibs, or drags dynamic changes or certain techniques is going to notice that when using a metronome. Some people just have an issue with basic time, which I assumed the OP was talking about because they mentioned using a metronome and it not helping...and in those situations, just more metronome, not on every beat, awaken the inner timecode.
My experience is that all aspects of musicianship and technique can be broken down into smaller elements that can be isolated and rationalised for the purposes of technical improvement. Timing in particular is one of the more complex aspects - co-ordinating finger speed, position and angles with hand position, string tension and length, dynamics and other elements of articulation is highly complex. Just bashing stuff out to a metronome without purpose is not always the most effective approach. If you play with a pick and your timing goes adrift when playing off-beat upstrokes whilst shifting, practicing downstrokes in straight quarters in position won't help the situation!
But, as always, YMMV
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