Never really cared for lots o buttons, especially if they can be brought down into one (like a lot of jobs could be)- personally am enjoying PvP kits more than normal kits (on average) due to identity and lack of button bloat feeling. I am aware some people like lots of abilities, I just don't personally need it. Partly I enjoy the PvP kits because each job feels different and brings something interesting to the table.
I actually quite enjoy SMN at level 90 and think it's my favorite "Summoner" of all the summoners. I think ARR's mechanics were very good, it just was a bad "summoner". Current Summoner before you get the special bloodpact aetherial rite whatchamecallits around level 86 is really simple though.. I feel they should bring that mechanic much earlier and do something with perhaps a new primal flavored skill that replaces physik (which is so useless it's not worth putting on your bar or remembering you have it).
Paladin is quite fun to play which I would have considered my main, but queue are like 5 mins for me even for old content on DD and so I've been enjoying catch up on SMN as I can go in blind and not ruin the party (I never go in blind as the tank, too much potential fun killing for others).
Before EW had suggested they go through each job and attempt to add as much non-savage/ultimate like flavor as possible (roleplay gameplay), mostly exploratory and fluff, to add some feeling of differences, but since EW and all jobs getting a more similar vibe.. feels like they can hopefully capture combat 'differences' in the next expansion. (The quick and dirty example is why does Dragoon take fall damage, or in zones with flying it would be logical if they could manipulate their jump to jump farther (by holding down the spacebar before and during 'flights')).
I play each job a bit, but not so repetitively that things are too painful when similar, but one that stood out to me as 'but y tho' was when each tank got essentially a Fel Cleave phase. We all became part warrior lol. More recently they made the dragoon jump no longer a jump, I'm sure it would have some balance implications for some content (if minor that's fine, imo) but I thought adding a % max hp shield and movement speed boost could have been a more fun way to give dragoon's the ability to manage they're actually jumping to a location.
Certainly there are still differences but it seems like there is a minimum of 2 steps forward to similarity for each 1 step of difference.
I would probably say the most concerned job, even though I don't main it, is healers- they do have to heal when content is brand new and people don't know / don't have good gear.. but it quickly becomes less important in a lot of content. Given what they get to do outside of healing is like 3 abilities... that's a bit unfortunate lol. My suggestion rather than having to change a bunch of systems on their head (impacting all the other roles) is to split the healers between offensive and defensive support actions and then add many skills to that effect with less healing skills (still can heal, still helpful when needed, but a lot of other things to do too). For example Scholar prior to losing all their attack skills and rotations and healing fairy power would be more in line with an offensive healer. Defensive support would still have damage too, it's just the theme / target. So players who like being a battle healer vs a team player. Astrologian being defensive, improving their card systems, etc.