My Opinion on blandness:
Gen 1: Honestly, charmander to charizard is the most bland even if you include Mega evolutions. The changes and overall details aren’t apparent and the concept of “dragon” was already being used so constantly. After that, I’d put blastoise as the next most bland and venasaur is probably the least bland of them all considering the concept and the details are more apparent due to foliage and stuff.
Gen 2: Blandness wise, I think it would be safe to say that Cyndaquil and Chikorita is the most bland with detailing. They just don’t have as much detailing as Totodile, but I find totodile more bland as a general concept or at least less creative. I mean a Porcupine creature with spikes of fire and some green monster with grass(very reminiscent of bulbasaur though). So you could argue over blandness but it depends on the base of the topic being originality/Concept, detailing, or etc.
Gen 3: PERSONALLY, I’d say none of them are so bland, except in concept. Mudkip and Torchik(OG FIGHTING FIRE) are definitely not bland in concept and Sceptile and Mudkip aren’t bland in detailing. The mega forms definitely also accent their general appearance as well and doesn’t make it any more bland as well.
Gen 4: Ok, so Piplup is the least bland in concept, Chimchar had already been done in another method so definitely bland, and turtwig is just another grass leaf Pokémon that they overdid. The details aren’t bland at all though. They definitely have more detailing to their mix and more “parts” than their predecessors at least and that counts. Unfortunately, they didn’t have so much originality and their designs probably weren’t favorable nor their typings, excluding empoleon but it’s overused to some extent.
Gen 5: In concept, honestly, all of them are pretty unique as far as what Pokémon did introduce. Though, some of them less unique and interesting but a bit appealing to some, >glares at Snivy<. But the designs are very much not bland and interesting to their own extents and bland really wouldn’t be a way to describe them, if any word should be used.
Gen 6: Alright, so some of these are quite bland in concept, >hard glare towards fennekin and froakie as well as the general idea of “Firefox”, “Ninetails, Naruto”, And “Frogs summoned by ninjas”.[Not that I mean anything by that]<. I’d say chespin’s final is actually the most unique by the bunch considering concept and is definitely the least bland since despite being the typical tank looking grass type, he has a different color shade and appearance that is much more different from the typical grass type. Meanwhile, Fennekin’s final and froakie’s final are far less unique and much more bland as they fade in with the starter bunch typical colors.
Gen 7: Alright, the concepts here can be argued with originality. As far as I’m concerned, Litten is the most original of the bunch>even if I dislike the final form<. In terms of details, popplio has the least bland in final form of the bunch. Their forms and stuff aren’t so much noteworthy, though, as they follow the typical color shades to some extent and the entire idea behind two of the designs are quite bland or so to speak. Moving on!
Gen 8: Well, best way to sum this up is... yeah, no... this would be extremely bland. Even more bland than Gen 1 if you compare overall general details between the generations of their times. The designs aren’t so unique as far as the typical outlook of how things are to go and grookey is probably the most unique out of the bunch in terms of concept. Then we also have the matter of details being far less noticeable with grookey being at the peak for details... so yeah. Nothing else much to say about that...
And there is my flat out opinion on the blandness levels of the starters. I’d applaud you if you did read this, but I can’t actually tell.