What you are actually getting
Let's be straight with you: these are not going to replace a proper pair of Levi's. Amazon Essentials sits in that budget basics bracket, the kind of thing you grab when you need an extra pair for decorating, muddy dog walks, or the fact that your old jeans finally gave up. Stretch denim, straight fit, medium wash. Nothing exciting, nothing offensive.
Personally, I think the stretch blend is the one genuinely useful thing here. A rigid budget jean at this price would be borderline unwearable, but a bit of elastane in the weave makes a real difference to comfort if you are on your feet all day.
The honest reservations
The finish is not going to fool anyone. Up close, the stitching and the fabric weight feel exactly like what they cost. The waistband can get a bit uncomfortable after a long sit. And sizing on Amazon own-brand clothing is always a bit of a lottery, so check the size chart properly before ordering.
That said: 669 degrees of community heat on HotUKDeals is not nothing. Real people voted on this with their wallets and their upvotes.
Who this is actually for
If you need a functional pair of jeans for around the house, a spare for the car boot, or something your teenager will inevitably destroy within a month, this is spot on. If you are looking for denim you will wear to meet your partner's parents or want something that lasts three years of regular use, look elsewhere. At this price, you are not buying quality. You are buying convenience, and sometimes that is completely fine.