Upgrading to Catalina with ease: or not upgrading (at least not yet). If no upgrade is that the end of updates for security purposes?

https://support.apple.com/kb/sp803?locale=en_US&viewlocale=en_US

The technical specifications article and all other links connected to Catalina upgrade,

for example the 'more info' link that appears when upgrades are presented on one's

computer are essential reading. They in fact pre-warn of all the difficulties that I am

reading by users, in regards to the upgrade, for example amount of storage space

required by model year of computer (in the footnote of this linked article.)

Have previously read tech opinions that one doesn't need to be 'the first one on the

block' to upgrade, allowing time for Apple to iron out difficulties before jumping in.

I see that the upgrades present improvements in areas that are not of much interest

to my simple needs in computing, so it doesn't at this time appeal to upgrade the OS.

Regret that without upgrading I will lose updates of security, which will only be for

Catalina (or whatever the latest OS is) -- am I correct in this understanding?

Using a late 2013 MacBook Air; Mojave OS 10.14.6

Have been enjoying the sense of security in updates for security purposes with Mojave and

am sad to lose this option, if my understanding is correct that none will be provided unless

one is on the latest OS. 😓