As someone who held onto the iPhone 5S for years after its EOL and then held onto the iPhone SE first gen for as long as possible (until a cracked screen and second shot battery forced an upgrade) I can confidently say this guy is missing out.
I held on to the old phone because of my thinking of the "stability and perfection" of its old design.
I avoided the iPhone 6/7/8/SEv2 era like the plague because of just how unfinished it felt. It was slippery, it felt uncomfortable in the hand, and I hear it was not the best at repairability. It also just does not look good in my opinion.
At the time THAT phone felt like the one was was unfinished. Now this guy is saying its the one that is "like a well-finished product". Its the same design that I felt was unfinished. I conclude that this talk of finished vs unfinished design is just a matter of taste and perception. There is nothing that fundamentally changed from iPhone 8 vs iPhone SEv2/3. It still inherits my complaints from above.
In reality he just hasn't put in the time to give the iPhone 13 and iPhone 13 mini designs an honest chance. They are the current "unfinished" designs. A few years down the line he will be saying the same thing about that design once it comes out in iPhone SE v4(or 5/6/7 whatever).
Now to be fair there is something great about small cheap phones that pack a lot of value. It is just what it is. Last gen design that some prefer while others do not. Its not anything special nor "perfected".