"Modern" cars (since 1930's?)
I had a 1964 International Harvester Scout with a three speed, but synchronized 2nd and 3rd only. I think my 1964 Ford Fairlane also had synchronized 2nd and 3rd only.
I presently have a 1969 Saab with the freewheeling mechanism still functional. I need the clutch to start rolling in first, but once rolling no clutch is needed for up shifts or down shifts. Release the accelerator, move the shift lever to the next higher (or lower) gear, press the accelerator.
My 1996~97 VW TDI never had a clutch-starter interlock, nor did my prior 4 VW diesels, Renault, Audi or prior Saab, as this ability to move the vehicle under starter motor power is considered a safety feature. I happen to agree with that opinion. I don't believe any of the manual shift European cars I've owned / driven have had clutch-starter interlocks, But I can't remember them all (senility?).
Don't make generalizations about generalizations.