I do think most government agencies are crap. The only one I have encountered good were UK ones and they have a pretty strong and interesting stack. They showed a talk at a MozFest where their compatibility went back to Next browser iirc. Due to the same reason though some of their relatively simple forms are multiple pages since from what I understand they don't allow "branching sections" in a single page

https://www.youtube.com/watch?v=Ik9IeChLqEk (think it was this one)

P.S. I think US is worse in every aspect. Try booking a US Visa appointment. Also as someone who has done both, Indian tax filing is significantly better as compared to the US where a government site doesn't exist. The worst offender in India was the driving license portal. (Older forms did use to be a weird excel UI and getting it to work on libre office was a nightmare I abandoned)