Quoting Casey Handmer’s blog:

One day you will die.
You only get a few chances to work on really big projects, to build the future, to move humanity forward. Choose wisely!
“What sort of project should I work on?”
It should be something at the limit of your capability, so that you grow the most and have the most leverage.
It should be something that you, personally, need to see exist in the world.
It should be something that would not occur if you don’t do it. You need to seek out inefficient markets for effort.

SaaS is mature – there are enough smart people working on every possible permutation of code that your particular marginal addition is unlikely to accelerate the future by more than a few weeks, maybe months. The hardware sector is not mature outside of a handful of extremely restrictive verticals.
Most hardware concepts will never even be dreamed, let alone designed, built, and brought to market. There are many, many more important, good businesses to build than there are people building them. When you build something, you can accelerate the future by decades!

if your vision for the future includes hardware technology that cannot be bought but has to be built, exclusively running a gold mine SaaS project to generate wealth is a losing strategy – because the outcome is the same. No hardware unless you fight to make it real.
“But I don’t know anything about hardware?”
No-one does. Humanity is still in its infancy. It is true there are people that know more about particular kinds of machines than you do, today. But nothing they learned is beyond your intellectual capacity to deeply understand and all can be learned in finite time. Step One is to admit that it’s time to read books and ask stupid questions. Step Two is to spend a year or three in the trenches climbing a new tower of esoteric knowledge.
This is time consuming but it is a necessary precondition for success. The class of sufficiently-interesting hardware startups must be founder-led. They must embody both the business and the technical side in order to find the intuitive clarity necessary to break out of analysis paralysis and actually build stuff.

No quantity of raw money is enough to make up for a lack of vision, a lack of grit, or a lack of commitment to see the idea function in the real world. To coerce rocks into coming to life and embodying a sentient idea. Everyone’s resources are finite. Time, skill, attention, and last of all capital are vital.

SpaceX has landed more rockets in the last 12 months than the rest of the world has managed to launch. This apparently impossible feat occurs roughly twice a week, and was first performed by SpaceX in 2015.

if you want to be 52 years old and have delivered millions of EVs and have landed rockets 220 times, you have to start today.