We have a much higher standard of living than before industrialization (the time before fossil fuels) so cutting all use tomorrow would lead to a lot of issues.

One major drastic action we should take though is removing our subsidies for the fossil fuel industry because right now we subside them entirely too much for having to get away from them. We could instead put those subsidies towards renewable energy sources and swapping out energy consumption more towards electricity instead of directly fossil fuels (like natural gas heating for homes, etc)

And as is tradition for many things nowadays: distribution and access to services is one of the biggest hurdles. The resources that exist that could support everyone are not evenly distributed and to do so is not something that can be done without energy costs.

A great example distribution hurdles is clean water. We have more than enough clean drinking water for everyone currently alive but to get it to everyone is massive hurdle as there are parts of the world thousands of miles from clean and safe drinking water.

We have to have proper plans in place for moving to renewable energy otherwise things will go poorly. We should be doing more to make it happen faster though.

We should be dumping resources and money at this problem like the continuation of our species depends upon it, because it does.