Honda conducts successful launch and landing of experimental reusable rocket

Question why is it so easy today to build reusable rockets? Is it because the onboard cpu speed of the chips can solve more granular control problems with low latency?

Proof of concept. It's a lot easier to do something, if you know it can be done.

Its more about money.

If you know that something can be done, and there is a potential market for such a project, it then becomes easier to get the funding. Chicken or the egg...

One thing we also need to point out, is that SpaceX uses like 80% of their yearly launches, for their own communication / sat service. This gave a incentive for that investment.

Is the same reason why, despite SpaceX throwing those things up constantly, there really is a big lag of competitors with reusable rockets. Its not that they where / not able to quickly get the same tech going. They simply have less market, vs what SpaceX does non-stop. So the investments are less, what in time means less fast development.

SpaceX is a bit of a strange company, partially because they used a lot of the public funds to just throw shit at the wall, and see what sticks. This resulted in them caring less if a few rockets blew up, as long as they got the data for the next one with less flaws. It becomes harder when there is more oversight of that money, or risk averse investors. Then you really want to be sure that thing goes up and come back down into one piece from the first go.

A lot of projects funding are heavily based upon the first or second try of something, and then (sometimes unwisely) funding is pulled if it was not a perfect success story.

Even before SpaceX started launching their own satellites in huge numbers they had a business model where they were selling the launch, not the rocket, and selling it at a fixed price, so if some small refinement saved them 5% on launch costs it went to their pockets so they had an incentive to make those small refinements.

Dragon 9 was based on conservative and boring technology but it was cost optimized before it was reusable, then reusability crushed the competition.

For that matter, Starship is boring. "Throw at the wall and see what sticks" isn't "trying a bunch of crazy stuff" but trying a bunch of low and medium risk things. For instance, development of the Space Shuttle thermal tiles was outrageously expensive and resulted in a system that was outrageously expensive to maintain. They couldn't change it because lives were at stake. With Starship they can build a thermal protection system which is 90% adequate and make little changes that get it up to 100% adequate and then look at optimizing weight, speed of reuse and all that. If some of them burn up it is just money since there won't be astronauts riding it until it is perfected.