It isn't the client side who does this, it's the server side. Doing it on the client side has a nominal benefit in the typical case but is very little value to you when the problem is some misbehaving third party AI scraper taking down the server when you need to get something from it that isn't already in the local cache.
If you have three local machines, you might be able to turn three queries into one, assuming they all visit the same site instead of different people using different sites.
If you do this on the server, a request that requires the execution of PHP code and three SQL queries goes from happening on every request for the same resource to happening once and then the subsequent requests are just shoveling the cached response back out the pipe instead of having to process it again. Instead of reducing the number of requests that reach the back end by 3:1 you reduce it by a million to one.
And that doesn't cause any HSTS problems because a reverse proxy operated by the site owner has the real certificate in it.
Not really. At minimum you will break all of these sites on the HSTS preload list: https://source.chromium.org/chromium/chromium/src/+/main:net...
It isn't the client side who does this, it's the server side. Doing it on the client side has a nominal benefit in the typical case but is very little value to you when the problem is some misbehaving third party AI scraper taking down the server when you need to get something from it that isn't already in the local cache.
If you have three local machines, you might be able to turn three queries into one, assuming they all visit the same site instead of different people using different sites.
If you do this on the server, a request that requires the execution of PHP code and three SQL queries goes from happening on every request for the same resource to happening once and then the subsequent requests are just shoveling the cached response back out the pipe instead of having to process it again. Instead of reducing the number of requests that reach the back end by 3:1 you reduce it by a million to one.
And that doesn't cause any HSTS problems because a reverse proxy operated by the site owner has the real certificate in it.
Public key pinning was rejected so you just need your proxy to also supply a certificate that's trusted by your clients.