Hi Dheeraj,
Leadership is responsible for culture and strategy for problem-solving. I would look for projects under champions who are open to your suggestions to bring visibility to the potential of cross-functional / technology solutions. If you get a few wins, then may be you can shift the way other leaders approach the projects too.
Within LSS, for example in DMAIC, I would suggest asking for SME's from the needed verticals (e.g. RPA specialists) to become part of the project by the time you reach the "Define Phase Gate". This will be part of your stakeholder analysis as you scope your project.
If these SME's cannot be engaged, then I suggest making recommendations at each Phase Gate or Leadership meeting where you ask for their support on issue resolution so that they can understand the barriers and that the solution requires more resources to be most effective. Also, show the potential with RPA and without RPA as soon as possible.
Alternatively, you can categorize your recommendations by effort and impact, it may strengthen your business case to get the collaboration/solutions you seek.
Discuss the issues you raised with your management and leadership to get their attention on the wasted opportunities.
Lastly, there are organizations where the prevailing culture does not help the kind of problem-solving that matches & values your talent.