Sry to ruin your expectations, but one trick ponies, usually back in plat+ years ago had it easier.
And yes, there were a lot of one trip (riven only, lee only, etc) that couldn't play all roles.
If anything, expecting to play all roles at the highest level is bullshit.
Even in LCS they don't do that, and those players are payed to play shit fucking game. And you know why they don't do it?
Because to get good at one role, you need to practice. So, in the time it would take to get practice for all 5 roles, someone else will get 5 times better than you on a single role.
Example: Echo Fox vs Team Liquid last week. With Piglet (an ADC main for years) got CRUSHED by Froggen (a mid main) in the second game in a match-up that would normally be a 50/50 (enemy doesn't counter him, and he doesn't counter enemy laner).
So, while you will stay bronze, that other player will get into gold.
Sure, you will be better than them on all 4 other roles. But if you face him on his main role, you'll get CRUSHED.
That's why you see in challanger, diamond, masters people that are highly focused on a single role. Even if their champion pool is kind of wide, like lets say 5 champions. All 5 play the same thing.
The new champion select allowed selection of 2 roles, which not ideal is still a massive improvement over "having to practice all 5".
Not to mention that practicing 2-3 good champions in all 5 roles will take exponentially more time than 2-3 champions in 1-2 roles.
And yes, even something as little as Top to Mid are VERY different.
So, no. Old seasons't weren't more spectacular or hard once you got above silver where people started to understand what maining a position meant. In diamond + people started to know each other and let each other have roles they main in.
That's why, the number of 1 tricks was higher than right now.
The simple concept that you can play everything is bronze/silver. And last pick support was something I rarely saw after getting above gold. If anything, one of the first picks (first 3) will pick support to let their mid/top get a better match-up in their solo lane.
If I look back at season, most of my janna games were first picks. Coz, there's no real counter for janna + my team gets to get good picks compared to the enemy = higher chance to win = huge win rate on my janna
for that you go to champions and pick s5
https://euw.op.gg/summoner/userName=serika+zero
and you can see that overall, my kda usually sucks, but i win games. And my Morgana is a mid morgana btw. Not support, so, all morgana games (except maybe 2-3) are mid morg
And I used to be able to play 3 roles: sup (janna only), mid(morgana, malzahar, ahri, diana), top(fiora, akali).
malza got reworked, and ahri didn't get practice in a long time, so my mid pool is small again
top fiora got reworked, same for akali, so, my top lane now its random picks
So, if I don't get mid/top. I'll go "fuck this shit" and pick my worst champion for that role, unless i got adc mf available, then i might try.
Oh, I get auto fill into jungle? lets pick seju and farm all game
Got outfill into support? worship the sun all game and dive towers from lv 2 onwards
Got autofil top? ap ekko here we go
Got autofil bot? i only have the q button ezreal ftw