You're really close, yeah .

But because like every layer is checksummed both in delivery AND when it's installed, so you can easily validate a delivered file, and it's all signed with signatures you can easily check, you can at least be assured that

• what you installed is what that package delivered
• which is what the authors wanted
• and the package probably hasn't been tampered with
• even weeks after install

the chance of problems should be reduced.

Bonus1: with a proper repo config, you can check for updates so fast. It's like the chocolatey windows repo but more formalized and usually vendor-maintained.

Bonus2: bad upgrade? Enterprise packages on Linux (long description; trust me) can be reverse-installed over what's there so you can back-revise or downgrade with almost no pain. It's a good oh-no fix. At every point you can still validate that what is there should be there, according to hard signatures at every stage.

Bonus3: grabbing os version 6.1 and upgrading to 6.5 OR just installing 6.5 fresh gives the same final content - files and services - when you're done. (almost entirely) No cruft, since package installs (because of the locking below) just install over themselves in a way Linux people just accept and windows people may freak over.

Linux bonus: Linux locks file differently; again, long description, so trust me or look it up. You can upgrade many files and services without stopping them, and then bounce a service or a host, so your patch-and-bounce process is fast, it happens after the upgrades, and is like 2 min or with systemd 3min.

Ultimately

• use packages for wayyyy easier, consistent, reliable, tested, quasi-roll-back-able updates that you can validate all the way down.
• and still that SNMP connection to check content remotely. It's so great.