Can you convince a market to adopt your solution?

Totally agree.

I like to think of it in terms of your customers' budget. That could be a literal financial budget, or an attention budget.

If you are trying to sell someone something it likely needs to displace something else on their P/L statement, or it needs to displace something else taking their attention. We can see that kids for example are spending less time watching traditional TV, and more time watching YouTube videos, and on social media. We only have 24 hours in a day after all.

For a SAAS product it is much easier if what you are building displaces some existing line item on their budget. That should really really focus you, because the reality is there are only so many SAAS products a small business (or large business) is going to need. If it is NOT something on their existing budget it is probably because something has fundamentally shifted in the world that means they have a NEW problem to solve. For example, when email started becoming a popular tool for communication in the 90s businesses would have started need a way to maintain email lists and to mass email their customers.

The challenge with creating something truly new, is that you're going to really struggle to communicate what they need you for. Educating a market is really hard, and really expensive. You need to convince them that adding something new to their budget is going to be worth it at the end of the month/year. Will what you're offering allow them to increase revenue to more than offset the price they pay you.

Also, just because you've created something truly new, doesn't mean that the underlying need at the root of it is new. In my email example above the method of communication might have been new, but at the root of it a business needs to be able to communicate with their customers.

I could see a case for the "truly new" products being better suited to the VC funded world of startups where they are comfortable with the higher risk, and higher cost associated with educating a market. For example, Salesforce 20 odd years ago raised enormous sums of money to help them educate the market on "No Software" to help people get their heads around the cloud. This helped to lead the way for other businesses.

I think the best indicator of their being a market need for what you want to build is that they are already solving this problem using a collection of Excel/Google Sheets, Zapier Zaps, etc. Basically digital duct tape and glue.