As for the speed, it is not overwhelming… but perhaps your MBP has just PCIe x3 , not x4?
As for temperatures:
apple has a long „tradition“ that means not only „function follows form“, but also „low noise priority whatever temp. Will cook the electronics“….
As someone who learned this by the hard way, I have installed MacFanControl to overcome this problem.
you can chose the bad default program from apple for cooking their electronics - or just select two of the sensor temp (free choice) and set the lower temp. Where you want the fans to start moth more rpm and set as well the max. Temp. You want.
It depends surely a little bit of the way you use your MBP, but after all the years I chose CPU average 47/65 degree C. And about the same for the platform controller Since these two are those locations where the temp. Start to go up first.
I like a second app a lot to block or activate my dGPU with
https://gfx.io/ (gfxCardStatus) manually with just one click.
so you protect your GFX card if no need for the dGFX and the internal GPU is enough (which is more often the case than many people think). Nice point: you save energy doing this.
If you use often your dGPU you might chose its temp as one of the two sensors to set to low and high temp to protect the dGPU the best possible.
I use these two apps since at least 5-6 years now and appreciate them very much (thanks to their developers!).
It takes some time to adjust MacFanControl perfectly to your personal profile of use but it is worth it.
And since this app shows you with one click the temp. of all your sensors and you can also very fastly change the algorhytm to your special needs I highly recommend this app as well as GFXCardStatus.