You had not previously specified which branch you are using.
Without any clear indication of the branch being used it’s a fair assumption that you might have been using the Stable branch.
In this case it is also a fair suggestion to switch to Unstable (or Testing) for the purpose of comparison and testing against newer packages; a different environment.
If you are suggesting the issue you are experiencing is somehow Manjaro specific, thus far there doesn’t seem much information provided that might help confirm or deny that.
All I can suggest is working with – rather than against – those wishing to help, so that a solution might be reached.
If you haven’t found a solution after keeping a well maintained Manjaro Gnome system for more than two years (I too find this incredible) is to perhaps use one of the other distributions mentioned.
BIOS
I note that your BIOS is rather old. Updating to the latest (non-Beta) BIOS is often a smart move; and can often solve issues you might not even be aware of.
In this instance, BIOS version 1.2.7 released on 2019-05-09 – marked as critical – is available from the Dell site:
I’d suggest contacting Dell for instructions on applying the BIOS update; do this if only to address the security issues listed.
KERNEL
I notice you are using kernel 6.11.
Kernel 6.12 (LTS) is expected to be generally available this month. Switching kernels might improve things to some extent, though with a laptop of this vintage kernels 6.1 (LTS) or 6.6 (LTS) might also be worth trying.
Other possibly related articles:
- Some programs taking a long time to launche
- Comment from Unstable Update 2023-05-06
- Marked solution from After last full upgrade apps loading very slow – this may be pertinent with respect @cscs’s comment above.
- General search results: Gnome apps slow
Good luck.