FYI,
You really didn’t have to upgrade/update your iOS.
The news media has really been over hyping/over obsessing/ over reporting the actual seriousness of the Spectre and Meltdown CPU flaws/vulnerabilities.
This Intel CPU chip flaw is too early in its discovery to know what any electronics and computer manufacturers are going to do at this early stage.
This is a 15-20 year CPU chip flaw/security flaw.
Many users still using lots of older, legacy devices, computers and OSes.
There is really no way to know what Apple and other computing/electronics companies are going to do about legacy devices, computers and legacy mobile devices.
If you haven't had any issues all of these years with your iDevices and any other computing devices, chances are good that you won’t encounter any issues in the near or foreseeable future.
iOS is sandboxed and even Mac OSes still need user interaction/intervention to deny install of malicious code to allow an exploit of this CPU chip vulnerability/flaw from an unknown/untrusted source.
Currently, these vulnerabilities are still theoretical, as there have been no known confirmed reports of these vulnerabilities being exploited in the wild, as of yet!
So, as long as you are accessing trusted websites, NOT engaging in illegal web activities, like torrenting and pirating of music, video/movie media content/software and do not open emails and email attachments from unknown or untrusted sources, your exposure to this CPU flaw is negligible.
I am still using iPad 2 and 3 models and an older legacy computer with older OS and legacy software and I while I am just as concerned about these vulnerabilities, I am NOT too worried, at all, about my computing devices being affected/exploited by Spectre OR Meltdown security issues, as long as I keep as safe as I can online.
An exploit of these vulnerabilities would be targeted more toward governments, corporations and large banking instutions before a hacker would go after the average computer/computing device user.
The type of CPU/chip level code knowledge needed to recreate these security exploits is NOT something an average hacker is capable of implementing very easily.
The sky isn't falling!