When Microsoft talks about Extended Security Updates, the really do mean Security Updates. Do not be fooled into thinking this means "Support".
We had the fun and joy where a bunch of 2008 servers that had been migrated to Azure became unmanageable because while 2008 has Security Updates, that does not mean that Microsoft guarantees their own products will confinue to support it. In this case, one of the Azure Product managers decided to drop 2008 support as is no longer on MS's supported OS list. Mull that for a minute.
It also doesn't mean 3rd parties will support it either - you may find your backup or AV vendor no longer provides support either.
In short - just take the pain now and upgrade to a supported platform.