Germany saw the 1936 Berlin Olympics as an opportunity to show the world its work on television. Experimental TV broadcasting first started in March 1935, with a 180 line system, which was increased to 441 lines in 1937. WW2 halted further development. But after the war Telefunken became a world leader.
PAL was adopted for most of the rest of Europe (except the Soviet bloc and France who opted for rival Secam). Walter Bruch was still working at Telefunken when well into his eighties.
The UK’s EMI administered the PAL patents and very cleverly used them to make Far Eastern manufacturers build factories in Europe if they wanted to sell TV sets here.
After developing PAL, Walther Bruch carried on working at Telefunken. There were several attempts at making PAL a 1250-line widescreen HD system, such as Enhanced PAL and PALPlus.
Engineers took multiple test pictures using different systems to compare the results and look for subtle differences. But it was all superseded by the coming of digital.