For a while now the transition away from Manifest V2 (MV2) to MV3 has been on-going and it looks like it is entering its final phase of deprecation, at least, in the case of Google Chrome. A recent discussion thread in the w3c WebExtensions Community Group GitHub repo has highlighted how the latest and upcoming versions of the most popular browser are expected to be its final releases with support for MV2 extensions.
What this essentially means is that the tricks and bypasses that were used to keep MV2 extensions like uBlock Origin and others alive will not work any more on Chrome, or at least not for very long. For example the Windows Registry mod that could extend MV2 availability will cease to function after Chromium version 151.
I think the other browser in your list have little choice, since they use the chrome rendering engine. Only Firefox still has it’s own engine.
If you are on iPhone, you can use Kagi’s Orion - it is based on Webkit, which is what Safari uses. I have uBlock Origin installed on that browser.
If you rely on the extensions API you have no choice. If those browsers want they can just add ad blocking somehow, the code is open source. In fact Brave has its Shields applied directly in the source code without relying on the extensions API.