ESI and EPFO discrepancy - Why are there fewer establishments covered by ESI Act than EPFO Act?

Why are there fewer establishments covered by ESI Act than EPFO Act?
The reports of MOSPI indicate that there are over 4.5 crore EPF members, and about 3 crore ESI members. How can this be when the EPFO registers all employees making less than 15000 at establishments with 20 or more workers, but the ESIC registers all employees making less than 21000 at establishments with 10 or more workers.
Is it easy to get exempted from ESI scheme?

Primarily because while EPF is universal, ESI applies only in notified areas. Where ESI services are not provided, such areas remain excluded till the services like dispensary reach there. ESI has been increasing its geographical spread and with industries coming up even in remote areas, the covered area is on an expansion mode.
As regards exemption from ESI though there is a provision to exempt it provided there exist equal or better facilities, it is virtually impossible to provide matching facilities like medical coverage to employee and family, sickness benefit etc. The other option is to enhance salary levels to above the ceiling limit, presently Rs. 21,000/- pm

My view differs, over the years epf has improved its functioning with a view to focus on serving employees and providing more faster benefits.While esic has tough procedures to extend benefits to needy due to lack of reach and upgradation in the system.
For example, you can now resolve much your problems online in epf.but esic does not have such facility to reach out to people who needs it.
Though esic has large set up, it proves difficult for employees to smoothly resolve their health problems or benefit issues.
As compared to private health service providers esic lacks in speedy sttlement of benefits.
So most companies even opt for private medical service providers.
Key is Health related issues need faster attention than any other like epf,which esic should work on this aspect.

Thank you both! Is there a list of companies exempted from ESIC? (there is one on the EPFO website for PF but I didn't find one for ESIC)

The organisation I worked with (a navaratna PSU) had exemption from ESI till mid-90's, our later applications got rejected because the medical leave provided was much less in comparison to ESI Scheme though the medical benefits, facilities and coverage of family was much better. We have in house medical facilities upto tertiary care and all family members are covered, the employee and spouse for their life time entirely free of charge and that too for all medical eventualities.

@HRPRO
ESIC membership can be ceased after exceeding 21000/- but EPF membership continues till age of 58. and once the active UAN is generated, the employee can not be categorized as excluded employee unless he/ she attains 58+ of age
ESIC data is only for contributory members, while the EPF data contains dormant members also. i.e the members who worked for few years and presently not working or working in a non EPF organization, but their PF accounts are active and incurring interest