[linmob]

postmarketOS provides tooling, documentation and a helpful community ... at some point, you'll need to put in the work, or sell your used devices and buy other, better supported used devices to work around this.

Is it really unfortunate that there's no (known) mainline/close to mainline touchscreen driver for the Pixel 4a? Absolutely. But it won't magically appear without somebody putting in the necessary effort.