Anecdotally, I haven't noticed too much pain in crafting cross-platform scripts in PowerShell 7+. Most of the platform differences I've seen in PowerShell are at the "module level" (library of "commands/cmdlets") and most commands that are in platform-specific modules generally are pretty obvious that they are platform-specific modules. A lot of modules are cross-platform.
The biggest shift is learning to trust PowerShell commands/cmdlets and operators over platform-specific binaries like awk/sed/grep and so forth. A lot of those tools and manipulation steps can be done with native PowerShell commands/cmdlets/operators, but it's definitely a journey to thinking in PowerShell terms (that the linked repo looks like it can help with) and using/trusting its object-based tools, especially if you are used to the extended Linux shell text manipulation tool chain as "conversion" between the two paradigms isn't always straightforward.
The biggest shift is learning to trust PowerShell commands/cmdlets and operators over platform-specific binaries like awk/sed/grep and so forth. A lot of those tools and manipulation steps can be done with native PowerShell commands/cmdlets/operators, but it's definitely a journey to thinking in PowerShell terms (that the linked repo looks like it can help with) and using/trusting its object-based tools, especially if you are used to the extended Linux shell text manipulation tool chain as "conversion" between the two paradigms isn't always straightforward.