I think this idea could be true for some businesses, primarily those that only use their endpoints (laptops) for simple documentation tasks and/or as gateways to web-based tools. However, in addition to "user demand" there needs to be an adequate business case ($$ savings) plus enough technical knowledge on the IT implementation side to made the move. I've worked in shops moving from a large Microsoft Windows footprint to Apple products and it is not always an easy transition, even with tools like Jamf.
Since companies will still have to rely on a Windows- or Linux-based backend (on prem or cloud) they'll need admins that can handle integrating those macOS and iOS devices into their MDM systems alongside the Windows systems. There are also a lot of users out there who may have no experience with using a Mac, either for personal or business use, that will need re-training to use a Mac laptop. Both integration / transition of systems and users will introduce delays and downtime into a company's business processes, increasing the cost to transition.
None of the above is a reason not to move from Microsoft to Apple, but it's definitely not a simple process and that can lead to slow (or no) transitions for large businesses, no matter how many users ask for it.
Your ISP controls what ports you can access using one or more firewalls and traffic control devices somewhere past the point where you connect to their network.
They can block whatever ports they want. The only way around this is to use a VPN, which creates a tunnel directly from your device to a remote server to route traffic. This still goes through your ISP and whatever firewall they have but does so over a port that they (probably) don't block. They can't see what ports your web or network requests are using so they can't block it directly.
Depending on your technical know how and what type of router you have, you could set up a VPN at the device level (PC, phone, etc.) to send just requests from that device or at the router level which could send all traffic from your network through the VPN.
It's important to remember when using a VPN that the VPN servers can still see (and potentially log) all of your traffic, even if your ISP cannot. You still need to find a VPN service that you trust to not monitor your traffic.