You'd be surprised at how cheap, relatively safe and reliable bus services are in those regions.

Source: me and my wife traveled extensively by public transport in, well, at least Pakistan. The other countries are indeed sort-of hairy, but mostly for job-clearance-related reasons.

10s of thousands of religious pilgrims travel by bus between Pakistan and Iran every year. You can just avoid Afghanistan.

Generally the border between Paxistan and India cannot be crossed though. I believe Attari/Wagah is the only place, and it was closed too last I heard.

Indeed, it has been closed since the aerial clashes last year. But we can hope for peace, and with it cross border tourism.

Can locals still cross at Kasur/Ganda Singh Wala like before 1971?

To my knowledge, no. In the recent past, either you could cross via the the Wagah-Attari border crossing or get on the Thar Express train [1], which connects Karachi with Jodhpur via the Zero Point crossing. But the Thar Express has been closed since 2019.

[1] https://en.wikipedia.org/wiki/Thar_Express

They should avoid Pakistan if they can, not Afghanistan. It’s in relative peace while the border region of Iran/Pakistan see regular fighting between Pakistani forces and Baluch separatists[1].

1. https://en.wikipedia.org/wiki/Balochistan_Liberation_Army

There were some bad roads in the Balkans as well.