Windows 11 upgrade remove windows 10 issues?

I recently had some of these problems. They largely went away when I did a clean install of Windows 11. Now its very fast, whereas the version that I installed over Windows 10 was slow. The main reason Windows upgrades can be slow is that the files of the old version of Windows are still on the PC to some extent, and pre-Windows 11 versions of applications.

Fresh install will resolve issues (well, get rid of them as it is fresh), but this way it wont carry settings/apps/files - make backup

As current windows is "in trouble", in-place upgrade might help, but to same degree might fail. Is your hardware Win11 compatible? Can you post you PC specs?

Have you attempted ?:
DISM commands
SFC /scannow

Sign-out ALL windows/MS365 related applications, then sign in again. I'd suggest to create another local admin account beside your usual beforehand.

Getting rid of Avast would help. Horrible A/V.

remove HDD
install new SATA SSD of 120-250GB with new Win. appoint as primary boot in BIOS
reconnect HDD for your data.

I had issues before when Win would be installed with original boot disk present in the system during fresh install

Samsung soft not needed for Win install - still available online, i believe. It would help if you would go for cloning(mirroring current 2TB disk to new 2TB SSD*).
* - there are options to clone to smaller size disk , but require to re-do partitions. Don't even start without backup.
120GB will be sufficient for OS and some basic software. It wont stand long for your data (doc, pic, vid)

Media creation tool available from M$ online:
Win10:
https://www.microsoft.com/en-us/software-download/windows10

Win11:
https://www.microsoft.com/en-us/software-download/windows11

Win 11 will fail as hardware not compatible, unless you take risk and use Rufus for media creation(would not recommend as mentioned earlier - might bite back in time).

activation:
If OEM computer - should activate
If purchased key - should be under your M$ account.

No harm to "read" activation key before proceed:
CMD as admin:
wmic path softwarelicensingservice get OA3xOriginalProductKey

Powershell as admin:
powershell "(Get-WmiObject -query 'select * from SoftwareLicensingService').OA3xOriginalProductKey"

As long HDD is disconnected, you still have it as "roll back" in case something go south
Once fresh Win installed, you can re-connect HDD and access you data. Your PC might get confused where to boot from as HDD still contain valid Win. Ensure SSD set as first boot in BIOS
I'd personally would back up data beforehand and then format HDD to be reused as storage once new install confirmed successful.

Personally i have C:\ drive for Win/programs only, even some programs/games installed on separate disk(s).
Data folders can be re-pointed to be on other storage - in case Win disk fail i still have data on other drive(s) with OS installed on new disk.
Software would need to be reinstalled/reactivated regardless.

re-pointing your folders (docs, pics,vid, etc) does not substitute as backup - any storage might fail at any time.

IF intend to, you can install SSD instead HDD as i'd disconnect it anyway during install .
SSD has no moving parts, so can just hang around, not need to screw-in.
Even without your data from HDD, you could see performance difference in real life.
Suite yourself