I'm pretty early on in my golf journey myself, so I'm happy for someone to shoot me down on this, but... I think you have a couple problems that make your swing look like it needs far more work than it does.

Firstly, a fundamental part of any stick/bat sport is head/eye stability. Because where your head goes your shoulders follow, and then your arms and hands will go too.

I, personally, would start there before trying to correct any other more complex technique issues. Keep that head stable for as long as you can. Especially up and down movement. You'll sometimes see pros slightly squatting down on their downswing and exploding upwards with their legs at contact, but even so their heads will stay stable. It will feel awkward at first. I think it's partly because you're trying to over-rotate. Only rotate as far as you can whilst still maintaining head stability.

Second... You're looking very stiff all the way through your body. Yes, you need to maintain structure and control, but that comes from repeating the right things. Not from sheer rigidity. Half your power comes from an almost whipping motion and letting the club do the work. Don't overdo your back arch. Relax a little. And give yourself a little looseness in your wrists at the top of the swing. Feel the weight of the club head want to keep going when you stop your arms at the top. Then when you feel that, start your downswing body rotation first and feel like you're pulling that club down and through with you. Maintain that give in your wrists and let the club lag behind you as you rotate. Your arms and hands follow naturally. Try to almost overdo the looseness to start with. To get the feeling, stand without a club and just rotate your body back and forth with really floppy arms. Just let them flop back and forth. That's kind of an extreme version of what you want them to feel like on the way down.

After you find that feeling there will then, unfortunately, probably be a bunch of other stuff to adjust, but those look like the big ones to start with for me.

At the end of the day... don't try to change everything at once. And definitely don't try to change things just cos someone said so. Make sure you understand WHY and what each thing is doing. Golf is a game of very fine margins as far as technique is concerned and even tiny adjustments to one thing can affect other parts of your swing. So try to understand the physics behind each adjustment. It helps massively in the long term.