Would it be more affordable if every country participating contributed an amount proportional to their GDP to help lessen the financial cost and burden for the host nation?
This would allow for smaller countries to host the Olympics and not have only a couple of cities rehosting it 2-3x when other cities have yet to even host once.
I feel like the best solution to solve the hosting issues would be to co-ordinate with the international federations involved in that year’s Olympics to ensure their world championships will be held in that city over the space of 10 or 20 years rather than the city hosting a lot of events in a short period of time to ensure the new facilities are being used longer. For example if the Olympics are being held in Brisbane in then maybe the 2042 World Cup should be held there too, then you could also hold a world athletics championship there in 2047.
I imagine you get to reap any tourist benefits that those places wouldn’t normally get over a longer period of time too (Paris as a place that normally received a lot more tourism didn’t really benefit from the games there).