A common tech fallacy is that legacy tech will go away if only you build a better version. Make something “better in every way” and then you can get rid of the old version.
When you own the software, you can force change. But you can’t do it by making something better in every way.
Once upon a time writing was only distributed on stone tablets and scrolls. Later we invented books, the printing press, and the internet. Each invention let us distribute writing wider with less cost. Even though it is more expensive and less effective, legacy “writing distribution tech” is still with us; we still produce writing on stone tablets, scrolls, and books.
When we first started distributing written ideas, the only way to get a copy was to find someone who had a copy, borrow it, and pay a scribe to copy it. Later, we invented printing presses which let us mass produce copies. Still later we created the internet which lets us produce infinite copies. Yet legacy “copy creation tech” is still with us; scribes still copy manuscripts by hand. We still have printing presses mass producing physical copies.
Whatever your system, whatever your tech, there will always be something “better” about legacy technology. Sometimes legacy tech is better just because the customer is already using it.
Your new system may be amazing, you may see it as better in every way; remember that your customers have their own opinions and reasons.