I'm sure this topic has been discussed by several people, but I will raise it again.
Over the last few years a specific issue has plagued photoshop. When you open any image file, whether it be a 10kb jpg or a 800mb PSD, there is a 4 second lag before you are able to click anything or use any keyboard commands. I have extensively tried to troubleshoot this issue doing the following.
-reset user preferences
-disabled hardware acceleration
-disabled antivirus services
-disabled adobe updater and other adobe services
-logged at least 20-30 error log reports to adobe with no response
None of these have had any effect on the 4 second lag. I first noticed this issue 3-4 years ago when using Adobe Photoshop CC 2019. Basically since the integration of Adobe Creative Cloud the overall stability and performance of Photoshop has significantly declined.
I am also experiencing another perplexing issue where if I leave a document open in photoshop overnight it will occasionally crash overnight while not in use. I'm unsure whether or not it is linked to the issue described above, but it would not surprise me.
This is a user to user forum, but I do hope Adobe staff sees your post.
In the meantime, I have long held a suspicion that these lags on opening files may be related to internet speed. Seems PS connects to the cloud, whether the panel is open or not - and that connection takes time to populate - as well as checking with Typekit fonts.
If you're on a wifi connection, I suggest testing for improvement via a wired internet connection.