My MacBook Pro webcam shows green light, but no image

the most frequent problem, if this has never worked, is that you have not explicitly granted permission for your VERY private webcam data to be shared with the Meeting apps you are running.

Settings > Privacy > camera

you need to allow each and every app that you want to have access.

other issues I see with your etrecheck report:

you have a third-party screen sharing app vnc running. This could interfere with what is on your screen or not on your screen. If you mean to share your webcam onto your screen with other apps running, then share that screen, you may need to extend privacy settings further to include vnc sharing, or shut that third-party app OFF.

If you intend to keep using this Mac for other purposes, you may have Over-upgraded this Mac that only 8GB of real RAM. Many users running Ventura or later are finding that only 8GB RAM forces one-at-a-time processing, where you can only run ONE major App before your Mac slows due to lack of RAM. you must shut down your Browser before you can have a meeting, of example.

¿What is the date of your most recent backup of the files on this computer, and by what method?

--continued--

A virtual private network, or VPN, is a private connection over the Internet from a device to a specific network.  VPN technology is widely used in corporate environments. If you need to be "present" on an institutional network, a VPN is a great tool for accomplishing this. it is generally issued and controlled by the institution.

Almost all other uses are a SCAM. There is generally no need for you to have a private connection to a VPN vendor's Network, except to make it easier for them to harvest your data to sell.

If VPN vendors just stopped there, it would be bad. But many of these packages also insist on scanning all your files, non-stop, -- nominally looking for viruses, but who knows for sure what data they are harvesting. Their non-stop file reading punishes your computer's performance in the process.

Some also break into your other secure connections so they can be FIRST to examine your data, often leaving your Mac MORE vulnerable to attack.