Personally, I think that working with salesforce is the worst of CRUD development combined with the worst of SaaS platforms. If you want fun work, I would not recommend Salesforce.
There are plenty of Crystal Reports professionals who found that their skills didn't transfer as the software declined.
Maybe the nuance you're looking for is it would be unwise to not progress your skills along the way. Like Salesforce Classic is a dead end, but if you transitioned to Lightning you're probably ok.
Or Tableau, maybe you should be learning Google Data Studio, Microsoft Power BI, etc... at the same time.
Learning a product is good. Basing your career from it is limiting.
It takes the professional to do that skills mapping.
Reporting systems are reporting systems for the most part. In the case of Crystal Reports, it was acquired by SAP and still pretty heavily in use in businesses.
Finding the best version of the role is part of being a professional too. At least where I am, there are lots of opportunities with mid-to-huge insurance/finance/healthcare companies that need this type of reporting.
They outsource a lot of the work, but they also have many slot for people with the tech skill and domain experience. If you were doing sales reporting, you could easily slot into one these roles because there is a need for someone locally who can talk to stakeholders versus someone at an outsource provider who can could be a great communicator, but has too many blockers at that type of inside company communication.
Small, meaningful efforts in such cases can vastly improve the actual quality of life of so many people.
The dream of tech working for people instead of people working for tech should include the majority, not a technical minority, no?