Try the boring option first
If an existing tool covers eighty percent of what you need for a few thousand rupees a month, use it. Custom software has a build cost, a maintenance cost and an attention cost that people forget to price in.
We regularly talk clients out of a build. It costs us a project and earns us a relationship.
The three signs you have outgrown the tools
One: your team maintains spreadsheets to fill gaps between systems. Two: your process is a real competitive advantage and the tools force you to work against it. Three: you are paying per seat for software where most seats use one feature.
Any two of those together usually justify a serious conversation about building.
Build the smallest useful version
The best first version solves one painful workflow completely rather than five workflows halfway. It gets used from week one, and real usage tells you what to build next.
Insist on documentation and code handover from day one, whoever builds it. The point of custom software is that you own it.