Thank you for the script, it is helpful to those that require Software based VSS backups and are having issues that are not obvious to solve.
Like MG stated, there is no one-size fits all solution with Exchange.
While lagged copies can protect from short term issues and in-place hold can retain data for a specified period. The issues are then with storage capacity for Exchange and whether the organizational compliance requirements allow for that to replace backups.
For organizations without Exchange storage concerns or compliance restrictions, such as requirements to store data off-site, offline or in a WORM format the in-place hold or lagged copies can work well. Organizations with those restrictions unfortunately have little recourse than using a backup solution.