It happens a lot. But it's not a matter of the class, it's a matter of the build you've chosen. You might just be playing a certain combinations of skills and items that either doesn't suite your playstyle, or that you need more experience with.
Here are two examples from my experience:
I loved the monk a few seasons ago and played it a lot. I loved the old Sunwuko set. But ever since it got reworked and is now heavily dependent on Sweeping Wind it just doesn't work for me. Just not my cup of tea. Which sucks, because it's by far the best set/build. So yeah, I only play the monk as support on season, and on non-season luckily I have godlike LoN gear so I don't have to use the SWK set.
Another example is the Manald Heal wizard. I have a lot of friends who are generally really good players, top 10 potential if it wasn't all just a paragon/bot festival (and who held top 10 spots before paragon/augments was the meta). And they're quick learners. But every single one of them struggled to get into the Manald Heal wizard. It just takes a few runs, and sometimes even a few days, of really feeling the true power. Once you do the MH wizard is the most powerful thing in the game currently when it comes to any speed farming activity - by a margin. But it's not for everyone, and it's not something that works just by copy/pasting the build. You need to give it some time.
Generally as a piece of advice, if something doesn't work don't bash your head against the wall in a GR that is too high. Go in a Torment rift and an appropriately low difficulty and just familiarize properly with the build. Learn each and every skill, figure out if there is a rotation and what can be maximized, and only go higher once you're really melting through stuff. A lot of people think "oh I beat this rift in 14:30 so I'm definitely too good for this, let's go higher". Yeah... not really - unless the build relies on having lots of mobs around and is supposed to be slow, going higher is never better.
It happens a lot. But it's not a matter of the class, it's a matter of the build you've chosen. You might just be playing a certain combinations of skills and items that either doesn't suite your playstyle, or that you need more experience with.
Here are two examples from my experience:
I loved the monk a few seasons ago and played it a lot. I loved the old Sunwuko set. But ever since it got reworked and is now heavily dependent on Sweeping Wind it just doesn't work for me. Just not my cup of tea. Which sucks, because it's by far the best set/build. So yeah, I only play the monk as support on season, and on non-season luckily I have godlike LoN gear so I don't have to use the SWK set.
Another example is the Manald Heal wizard. I have a lot of friends who are generally really good players, top 10 potential if it wasn't all just a paragon/bot festival (and who held top 10 spots before paragon/augments was the meta). And they're quick learners. But every single one of them struggled to get into the Manald Heal wizard. It just takes a few runs, and sometimes even a few days, of really feeling the true power. Once you do the MH wizard is the most powerful thing in the game currently when it comes to any speed farming activity - by a margin. But it's not for everyone, and it's not something that works just by copy/pasting the build. You need to give it some time.
Generally as a piece of advice, if something doesn't work don't bash your head against the wall in a GR that is too high. Go in a Torment rift and an appropriately low difficulty and just familiarize properly with the build. Learn each and every skill, figure out if there is a rotation and what can be maximized, and only go higher once you're really melting through stuff. A lot of people think "oh I beat this rift in 14:30 so I'm definitely too good for this, let's go higher". Yeah... not really - unless the build relies on having lots of mobs around and is supposed to be slow, going higher is never better.