FreePascal, that I believe is supposed to be reasonably Delphi compatible, supports
"Intel x86 (16 and 32 bit), AMD64/x86-64, PowerPC, PowerPC64, SPARC, SPARC64, ARM, AArch64, MIPS, Motorola 68k, AVR, and the JVM. Supported operating systems include Windows (16/32/64 bit, CE, and native NT), Linux, Mac OS X/iOS/iPhoneSimulator/Darwin, FreeBSD and other BSD flavors, DOS (16 bit, or 32 bit DPMI), OS/2, AIX, Android, Haiku, Nintendo GBA/DS/Wii, AmigaOS, MorphOS, AROS, Atari TOS, and various embedded platforms. Additionally, support for RISC-V (32/64), Xtensa, and Z80 architectures, and for the LLVM compiler infrastructure is available in the development version. Additionally, the Free Pascal team maintains a transpiler for pascal to Javascript called pas2js."
You do not get that much portability with many other languages. C, perhaps. But FreePascal has a bigger standard library and many other libraries that support many platforms. It is also a much safer language with checked array bounds and while there is support for low level unsafe things you do not have to use those nearly as often as in C. And while the compiler might not be as fast as Turbo Pascal (or Delphi?) it is still amazingly fast compared to any other compiler I have used this century.
What's not to like? Guess the lack of attention from developers and potential risk of there not being enough around to maintain it? I honestly do not know, but you do not hear much about it and not many projects seem to use it.
I’ve tried Lazarus a few times (on macOS), but I’ve found Delphi to be significantly more polished and reliable (including the more complex workflow of developing on Windows and running the resulting binary on macOS or in the iOS simulator — it just works).
I did consider becoming a contributor to make Lazarus better, so maybe something I should revisit.
The first thing I’d do is make sure Lazarus works perfectly on Windows, macOS, and Linux. For the other platforms, fpc excellence is fine, but they’re not important enough, I think, for Lazarus. One counter argument might be certain embedded applications but I suspect that would not be the right prioritization…
You can also use Delphi to produce Android, iOS, macOS, and Linux apps. All from single code base.