The costs of developing your software
Total cost of ownership
Has your security information office read the latest guide to information security testing and assesment from NIST?
Have they considered all the implications of what maintaining a functioning service means, to you, and have they prepared a plan for following the security standards and compliance, and ethical developments that will result in new requirements? What about law? GDPR? Once you have sorted that out, you will be left with some cloud providers, and now, you solved the TCO problem, but have to pay for infrastructure separately.
Cost of change
Once again, hardware not being an issue, software becomes one. Complying with new feature requirements can be tricky, not only because every line of code will require support and maintenance, but because it could complicate future integrations. We know that for a lot of complanies, webhooks is still not a thing, but it will, and having a properly documented and built API, also takes a village.
Emotional Costs
Developers, support, even sales, will become attached emotionally to their creations, and will believe that no other software provider can replace their systems, because the business is "unique", and might pass on acquiring the right tools for the right moment, or even stop using one. Also slow pace of change, is no good as it keeps staff unaware of the possibilities they are missing, and personal development opportunities could be disregarded as threats to the status quo.
Who should develop software then?
Software companies should be the ones developing their own solutions, no tool will remain unchanged, and your team should grow used to the only constant in this crazy world. Also, if you have a great tech team, and no one else is doing what you´re doing, you should keep at it, but recognize you´ve become a software company. Making sure your software will keep being usable, and up to date with security standards is what will make a difference.