How do you visualize your application landscape to classify and group apps by criteria like business criticality, technical fit, or cloud readiness? I’m exploring visual models for better categorization and would appreciate examples, tools, or frameworks that worked for you.

It depends on what the end goal is. If the end goal is to show the grouping then data can be captured in the XL and fed to PowerBI to generate the reports. If the end goal is to correlate the data and generate what Enterprise application  Portfolio then there are many EA tools in the market that provides the capability to generate the detailed report.

Either you use EAM-Tools (Alfabet, LeaniX, ..) or you implement your own visualization. One simple implementation I use sometimes is generating PlantUML-diagrams based on excel-data with Phyton