An increasingly mobile, and in more recent times remote workforce, has led to a demand to interact with SharePoint from a variety of different devices. Gone are the days when a user would sit at a desktop in the office and complete a form, which challenges many of the traditional ways SharePoint was deployed.
Microsoft has responded to this changing user behavior with a plethora of mobile apps & Canvas Power Apps, which is focused on mobile devices. Despite all these changes, it's hard to build forms of any complexity in SP that behave consistently across devices.