1. Observation: 80% of users only interact with 40% of the software
2. Conclusion: lets cut part of that 60%, since those are rarely unused features
3. Observation: 80% of users only interact with the 40% of the remaining software
4. Conclusion: lets cut..
You get the idea. In reality the most important thing is that users perceive your software to be able to solve their problems. If you want them to spend money you need to give them the feeling your software could also solve their problems if they came around in a slightly different shape. And those different problems may be covered by the unused features.
If you for example look at 3D software, that bone rigging system may be used by only 2% of users for 1% of the time, but a much higher fraction of users may not even consider your software if it doesn't have that feature in comparison to other software, even if they don't need it yet.
https://marketingscience.info/value-paretos-bottom-80/