TL;DR, as promised:

Established businesses are run at sustainable pace, while startup are run at sustainable determination.

Established businesses succeed with carefully planned stragey execution, while startups succeed with frantically executing a strategy of disruption.

Sustainable Determination

If you start a business, you have to be determined to make it work. And you have to sustain that determination until it actually does work. If you are not determined to build your vision without compromise, you fail to create a business or you end up with a half arsed version of the business you originally had in mind. If you cannot sustain that determination, you end up with no results for your effort. The end. Really. If you cannot sustainably show determination until the business works, what remains is what our industry likes to affectionately call "a great learing experience". That's startup speak for no revenue.

You have to be determined to do your new thing, because you don't have any other thing. There is no existing line of business that you can alternatively turn your attention to. There is no other revenue stream that allows you to lean back. You can not push back projects until some more favourable time at the risk of losing the opportunity. You will sometimes promise or sell some feature or product ahead of its production (software or otherwise) and then work your way out of that problem. You collect technical debt, and quite likely organisational debt, while building a viable market share. As a primary influence for any of those decisions, you don't ask yourself whether it's the optimal long term outcome. You ask yourself: "can the new situation be sustained or will the whole thing collapse when I do this?". Sustained long enough to reach revenue, profit, or exit. And then you make the decision with a determination to make the businesss work; not necessarily a careful consideration of the impact on whoever needs to do the work.

As an established business, you maintain a pace of excecution that is sustainable for your resources and workforce. This maintains a reliable revenue stream and controlled growth. That's what shareholders like. When your sustainable pace is not enough to maintain your market share, you investigate options for buying the capacity, either through sourcing or acquisition. It's not the opposite of hard work, but it is heavily de-risked compared to frantically satisfying all opportunities that could earn you a break through.

Disrupt!

Uber came to disrupt the taxi business. Tesla is apparently a whole new take on automotive. And AirBnB is absolutely not the same thing as a accomodation booking website. In spite of the fact that Uber let's you hail a taxi, Tesla will sell you a car, and AirBnB let's you, well, book a accomodation. These are all companies that sustained their determination to change a market for long enough, that a) there is a noticeable change to those markets, and b) the original founders made a worthwhile exit.

Does that mean that big automotive missed out on ride hailing and car sharing by just not caring about it? Do Volkswagen or Toyota not care about electric vehicles? Or Booking.com about small scale accomodations? Of course they do. To the point where Daimler has about a billion invested in ride hailing. And all major car manufactures are part of some joint venture on autonomous driving AI. And anyone running a serious small scale B&B or hostel that's not downright illegal will tell you that they prefer Booking.com over AirBnB (guess what, Booking.com has higher margins for the accomodation and better support).

You see, Daimler cares about ride haling in much the same way that Google cares about consumer privacy or Shell cares about renewable energy. They understand that in the end users will want this, but it's bad for present lines of business. Nonetheless, they are carefully executing on a strategy that prepares them for the tipping point, while minimising cannibalisation of existing business. It happens through investments, acquisitions, and launching new lines of business with little fanfare. Sometimes mentioning it as sub-sub section of their website.

As a startup, you have no incentive for slowly, and cautiously manoeuvring towards some future that you believe will exist, because you are not manoeuvring from anywhere. You are going from scratch and your highly innovative and drastically improved version of the future is the only one you sell. It's all you know and in order to make it stand out, you make sure it is perceived as a radical new approach to everyday things. Like finding a taxi, or a holiday accomodation.

Considering a Learning Experience?

Learning experiences are still great. Don't be discouraged. Just remember that if you are determined, you need to sustain that until profitability or exit. Sustainable does not mean the same for everyone, but for most people, it does not involve any hussle, sleeping under a bridge, or getting by on food stamps, so don't worry if you are not prepared to do any of that just to make your business work.