I love the narrative arc of saying that a problem technology was once the darling technology that saved the day. But, now that previous hero-technology has become the problem child.
This isn’t the tech’s fault, it just was allowed to wilt by vendors and users - it could also have been customized so much that it’s now unchangeable (e.g., many ERP and help desk systems).
There is a lot of empathy to have for “legacy” technologies!
When you want to say that the technology most people currently use is old, crufty, and unhelpful…and so they need to urgently get some new technology, you only need to make this point once and not spend too much time on the back-story.
Once you’ve spent 2 to 4 sentences being all like “you’re held back by your legacy stuff!”, what’s more valuable is talking about (1) what the desired, new, better end-state is, and, most valuable (2) how to get from here to there.
Your reader will know and be convinced that they need to change - otherwise, they won’t be reading your text/pitch. They are most hungry to know how.