This would not solve the issue and might even worsen it.

HVDC converter stations are absolutely massive and necessary to interconnect the HVDC line with the rest of the AC grid, making them larger targets than even the largest autotransformers (i.e. 750kV to 330kV like they seem to have in Ukraine).

If openinframap can be trusted, there are quite a few HVDC lines across India and China already, some in US, Canada and Brazil. It's not just the international underwater cables that use them. Not sure if avoiding large transformers is sufficient reason for using HVDC lines. HVDC conversion stations still need big transformers in addition to giant semiconductors and other high power electronic components which aren't exactly cheap or widely available either.

Hvdc systems still have transformers on the AC side.