Food delivery tech is really a challenging and real problem to be solved. It really have a potential revenue model and solution. why multiple startups fail after spending lots of money on it? If we can't build a sustaining business model why this is being built? From US to India most food techs crumbled.
Doubt it! Not only SAAS in every product there is an open market for alternate product atleast for 'popular products'. Alternate products just clone 'problem statement' and build their own version of the product solution.
In case of popular product, well developed or well defined domain first few steps of solution is going to be same which is unavoidable ex: A car will have four tyres. But, you have all the freedom to change it to be an electric car and make it better. This is how all better products are being made.
Any solution need product market fit, persistence, best engineering, trust among customers, support, experience etc.,
Spend your time in thinking "How this could be done better?". Then you need not clone any product. Almost all forms of idea is been tried in this world. We should try with our own skill set and experience.
All the best!