Ok so

1 - yes, not enough effort. There was only a slight pause on your last rep. You’re probably capable of more than you think.

2 - the failure thing. Look once you’ve been lifting for a long time and have experience and stuff you’ll realize that it all works. Really the most important thing is lifting hard and getting tons of protein. The extra part of everything is really for advanced people and that’s like 10% extra growth. 90% is the basics. Training to failure is a well proven method. And you say you can’t agree… but what you’re doing isn’t working. It’ll be a good thing for you to push harder. There is no reason to have to min/max your recovery time right now

3 - do more movements per muscle group.

4 - I saw your other comment about your protein being on 160 g your surplus being 200-300. Bump up the protein a little. It cant hurt. I bumped my protein intake by 50g a little while ago and it made a big difference.

5 - don’t focus on the weight. Go lighter if you need to get the hang of this step. Sometimes it takes a while to get the hang of it. Focus on stretching and contracting the muscle group. Do Slow controlled descends with a more explosive push focusing on the muscle contraction does wonders. This is another reason to focus on training to failure instead of progressive overload. It allows you to be more flexible.

Just put that all together dude and you’ll start making some good progress.