I am working with a client who is very resistant to my using MS Project to manage my program. The main reason is that they say "it is not collaborative." What they mean is that:
1. Using MS Project - client version - does not allow multiple people to edit simultaneously
2. Users must have a license to open the mpp file (expensive)
3. it does not have user-friendly ways of sharing the plan, reports and dashboards
4. I am not sure what else they might mean

They are now considering Smartsheet.

If you have encountered similar objections (or simply have opinions), how have you overcome these types of objections? How can I make the situation more collaborative, and why should we use Project rather than Smartsheet?

Maybe if I understood all the variations that MS offers, I would know how to handle this. I don't know what the functionality is in MS Project Plan 1, Project Plan 2, Project Plan 3 ... for example Project Plan 3 includes " Project Online desktop app". I don't understand what that is. Can I get by with that, or do I need MS Project Standard 2021, or Project Pro 2021?