How to validate the idea of ​​a SaaS with minimal effort, money and energy required?

I have been working as a dev in startups for 6 years, I always wanted to have my own product but I always felt unprepared to create something solo, for a while now I felt more confident, I decided to take a first step towards this dream, so I started to reflect on how to start, I reached a certain conclusion but I wanted to hear your experience and opinion about my idea of ​​how to validate a SaaS.

I created a small website where I positioned myself as a startup that creates MVPs, the idea in itself was not to show off immediately, and to centralize pages that will show my projects that are being validated, with the aim of not having to buy domains and upload landing pages for each idea that appears in my mind.

So I create ads and post them on some social networks trying to understand if the need is valid, the traffic would be redirected to my project page within the website I mentioned.

If the CTR was > 3%, I create a landing page and try to capture some leads, if not, I pivot and move on to the next idea, obviously when crossing this barrier and creating a landing page to capture leads, the next step is to build an MVP of the product. Depending on the situation, you could even create a wait list or something like that, even try to sell something to the first 100 subscribers with a good discount or something like that.

Do you think this is valid? Or am I just being lazy in validation and should I start building MVPs now? I'm afraid of spitting out solutions that are only useful in my head.