Can't play Sharepoint or Stream video links on iPhone

I am trying to store all our existing and future video files on Sharepoint but..... I can't get the shared links to effectively play on an iPhone which is the place most people will need to watch them the first time.  I fear my use case is beyond the technical capabilities of Sharepoint/OneDrive/Stream.  I read in a current white paper for OneDrive that the suggested bitrate is under 2 Mbps which may be the smoking gun here.

We have several hundred high quality 1 minute videos currently stored on Box and Dropbox that play and share great.  Mostly 1920x1080 h264 with a data rate of 35 Mbit/s.  It's the default YouTube export settings from Premiere so nothing wacky in their spec.  A 1 min file is about 300mb.  Often I send public links to clients to watch and then to download.  The vast majority of external clients want to view on their iPhone and will expect the video to start playing within 5 seconds of hitting the link, a totally normal expectation in 2023.

No matter if the link is generated in Sharepoint, OneDrive or Stream (and regardless of browser - I know you can't use Safari) the video wont play on an iPhone in any useable way like it will in Dropbox or Box.  If the recipient is on good wifi it may take 1 to 3 minutes for the progress bar to load and the video to start playing but most of the time the video never plays.  Obv a deal breaker.

I suspect im trying to get Sharepoint to something it's not designed to do.  Do anyone have any thoughts on how I can get my video files stored on SharePoint to play on an iPhone?  A work around?  Third party?  For a variety of reasons I would really like the files to be stored on our Sharepoint and not Box or Dropbox.  Thanks for reading.