Half of those PL teams were poor in Europe. The quality of the bottom half teams in the PL back then was far worse than it is now.
Arsenal have had many injuries so far, and City are in transition and without Rodri. Wouldn't be surprised if both teams were much better in the 2nd half of the season, perhaps Liverpool too.
Those generalisations about the quality of the top teams based on 15 games are premature. I'm sure many on here didn't think much about the Treble winners before mid February 2023. Actually, many thought the squad lacked quality lol.
The league as a whole is better now mate, I agree. The mid-table is stronger. However the quality of player at the top is poorer and a reason why it is more competitive now.
This league had the likes Luis Suarez, Aguero, Eden Hazard, David Silva, KDB, Yaya, Mahrez, Salah, Mane, Diego Costa, Rooney, Harry Kane, Son, Sanchez, Fabregas just to name a few all plying their trade at the top end of the PL 5-10 years ago.
Very few of that quality in the league now at the top end.
And in regards to the PL teams being poor in Europe back then. This was despite us having all that quality above, but the rest of Europe had the likes of Robben, Lewandowski, Iniesta, Ronaldo, Messi, Busquets, Neymar, Pirlo, Tevez, Kroos, Modric, Benzema, Schweinsteiger, Muller, Cavani, Falcao, Bale, Marco Reus, Ibra, Lahm, Alonso.
This is just to name a few names. Every single one of those players gets into every team in Europe right now.
The level at the top end is significantly poorer.