So what are the biggest restrictions affecting virtualisation of macOS today in the macOS EULA (available at https://www.apple.com/legal/sla/docs/macOSBigSur.pdf)?
(iii) to install, use and run up to two (2) additional copies or instances of the Apple Software within virtual operating system environments on each Mac Computer you own or control that is already running the Apple Software, for purposes of: (a) software development; (b) testing during software development; (c) using macOS Server; or (d) personal, non-commercial use.
Section 2B (iii) here gives a permission to run only two virtual machines on a Mac host, with usage restrictions.
Except as expressly permitted in Section 3, the grant set forth in Section 2B(iii) above does not permit you to use the virtualized copies or instances of the Apple Software in connection with service bureau, time-sharing, terminal sharing or other similar types of services
Translation: No VDI use, section 3 having:
(i) the leased Apple Software must be used for the sole purpose of providing Permitted Developer Services and each Lessee must review and agree to be bound by the terms of this License;
Which puts any hope of VDI being allowed to dust, and
(ii) each lease period must be for a minimum period of twenty-four (24) consecutive hours;
which is why AWS only provides you macOS instances with a minimal use time of 24 hours.
Except as expressly permitted in this Section 2B, you may not use the Apple Software to run any Apple operating system software, including iOS, iPadOS, watchOS or tvOS, in virtual operating system environments on Mac Computer(s).
Translation: You don’t have a license to run iOS & derivatives on an Apple Silicon Mac.