There are a couple potential answers to your question.
1) ‘make it up in volume’ - part of the reason for the relatively high capital cost of the technologies you are describing, is they don’t scale well from a one-off design or manufacture vs amount of energy produced perspective. Geothermal plants require significant amounts of ‘actually sticking a very long pipe into unstable ground’ which can’t be effectively economy-of-scaled away to be cheaper. There are also only a relatively small number of locations with the right factors to make it worthwhile. Presumably the waste heat systems you are referring to require custom fitting to the plant in some way, and there are also not a huge number of places with sufficient waste heat to make it worthwhile. Both of these techs are in the sub-gigawatt (often sub-hundred megawatt) range. That adds a lot of friction, thinking, and site/location specific ness for a relatively small amount of power. IN THEORY fusion can produce massive (giggawatt) power anywhere, and there is no reason you couldn’t make one for every neighborhood if you wanted. Please be aware that practically speaking this seems to be a fantasy.
2) most people don’t/can’t understand the physics, so it is really easy to project impossible benefits onto it that will never play out in real life, and sound plausible while doing so. This makes it easier to sell to politicians in particular.
3) IN THEORY because of these factors, whoever comes up with fusion first is going to take over the world (either commercially or politically), so there is a lot of pressure to not be #2 there. This outweighs things like pesky market dynamics and concrete profit margins.
4) also, since no one has a prototype or design for a reactor that could plausibly actually be a viable commercial reactor, no one has the ability to sit down and figure out if the math works or not. This is all still research reactor space.
1) ‘make it up in volume’ - part of the reason for the relatively high capital cost of the technologies you are describing, is they don’t scale well from a one-off design or manufacture vs amount of energy produced perspective. Geothermal plants require significant amounts of ‘actually sticking a very long pipe into unstable ground’ which can’t be effectively economy-of-scaled away to be cheaper. There are also only a relatively small number of locations with the right factors to make it worthwhile. Presumably the waste heat systems you are referring to require custom fitting to the plant in some way, and there are also not a huge number of places with sufficient waste heat to make it worthwhile. Both of these techs are in the sub-gigawatt (often sub-hundred megawatt) range. That adds a lot of friction, thinking, and site/location specific ness for a relatively small amount of power. IN THEORY fusion can produce massive (giggawatt) power anywhere, and there is no reason you couldn’t make one for every neighborhood if you wanted. Please be aware that practically speaking this seems to be a fantasy.
2) most people don’t/can’t understand the physics, so it is really easy to project impossible benefits onto it that will never play out in real life, and sound plausible while doing so. This makes it easier to sell to politicians in particular.
3) IN THEORY because of these factors, whoever comes up with fusion first is going to take over the world (either commercially or politically), so there is a lot of pressure to not be #2 there. This outweighs things like pesky market dynamics and concrete profit margins.
4) also, since no one has a prototype or design for a reactor that could plausibly actually be a viable commercial reactor, no one has the ability to sit down and figure out if the math works or not. This is all still research reactor space.