Windows 11 is basically a Win10 core with updates shell (icons, etc), other than cosmetic and some menu changes, haven't noticed any compatibility or significant bugs.
It does have a TPM2 requirement, which a lot of existing hardware doesn't contain or provide... thus not updatable to Win11.
Does your system under Setting / Update, indicate your system meets minimal requirements for Win11? Many older hardware does not.
As far as hardware, personal opinion... an i3 and unspecified RAM & GPU would likely be subpar in performance & satisfaction. The 120GB SSD is minimal for Win10 & Win11 but also the easiest to upgrade.
If your system is meeting your needs, I'd stay with current setup.