The beginning, the start, the show that gave birth to superhero television that was always something that one looked forward to when watching one weeknight, just that one hour of tv show to quench one's thirst: Smallville.
This show embodied small town America at its best and allowed relationships to come and go and the show to flourish in both its teen high school seasons to the mature and darker seasons that completed Clark and Lex's eventual animosity and the latter's descent into darkness. It let one get engrossed into the show and feel it almost tangibly. It was fun and enjoyable.
That feeling above that one has when watching these kind of shows is not felt when watching any of the arrow-verse shows. It's annoying, as however good a show becomes nowadays, very rarely will you watch it and revel in its plot.
For example, in Season 9, Zod was a forbidable villain that one never dared anger or cross and yet he was so complicated in that he never really had a major fight with Clark until the finale of the season. This allowed Clark to think about how to fight with his demons and finally get over Jimmy Olson's death and stop blaming himself for his death. Zod exploited this weakness and this allowed him to (almost) overpower him.
Arrow managed to just about use a similar idea with Prometheus, but still what happened in Season 4 and 3 was unforgivable.
Compare this to, what we think are Smallville's worst season's: 6 and 7. Neither of those even managed to be as bad as Arrow, because Smallville didn't do any stupid relationship arcs that weren't necessary and didn't make a villain that was so OP but also so weak that all one had to do was destroy a totem.
And the inspiration that Smallville had, with its purposeful lines, proper life lessons are not really found in any drama nowadays. Don't get me wrong. Smallville had some bad episodes, *cough*Thirst*cough*, but even then, the B-Plots rendered them watchable and not just Arrow Season 4 level trashy crap that is not redeemable in no way, shape or form. I mean seriously, why magic, like I swear that is for The Flash and not Arrow. Of course, Arrow could have a magical villain, but they should've made him grounded. Smallville kept most of its villains grounded but when there were some villains that were needed to be more, take-over-the world cliché villain, then they would make some amazing, passionate villains whose main goal was to destroy Clark specifically in the process.
Wrapping all this up, I honestly think that no superhero will ever be as good as Smallville by sticking to the classic protagonist vs antagonist formula, as well as fixing the writing. What Smallville lacked in cgi (which did get worse as the show went on...), it gained in good quality, meaningful television drama. Lets end with possibly one of the greatest, saddest and poignant tv moments I have ever seen: