I work for a security company. I don't directly work on the products, but I support those who do. While, as others have commented, it's not like in 200 years people are going to be studying my work, I do believe I'm having a positive impact on the world. It's a positive impact that in some sense I may wish didn't have to exist ("wouldn't it be nice if we just all got along?" and nobody needed security?), but, nevertheless, it does.
On a day-by-day basis it's easy to feel disconnected from the end result of what I do, since it is several layers of abstraction away from the end customers, but sometimes the customers will tell stories about their experiences and how it saved their bacon after a fire burned down their datacenter, or let them secure a critical service that was being attacked, or discover a vulnerability in their system before it was exploited, and I remind myself that I'm getting just a small fraction of the stories that could be told. I don't go cruising through the customer database, but in my normal work activities, I encounter schools, non-profits, governments, charities, normal businesses, all sorts of people who individually may be getting just a bit of benefit from my work, but on the whole, it adds up to a lot. I also find this a good motivation to sometimes put in just that extra bit of polish on my work even without being asked or having an explicit bug tasked, which is typically technical rather than visual-design oriented so you may not see it or feel it, but you might feel the absence of it.
You may want to take a certain mercenary capitalistic "value-added" view to the whole thing, because it's often justified. Working for a grocery store chain IT may feel unexciting compared to the wild exploits you read about on HN, but you are helping people buy food efficiently and ultimately more cheaply than they could if all the grocery stores had no IT. This helps everybody, and particularly helps those on the margins, i.e., the poor. Scheduling software for the professional trades brings efficiency and services to people on the margin who otherwise couldn't afford them. Factory-specific software brings wealth to society as a whole as it increases the capabilities of factories and such to bring wealth.
And let's be honest, a lot of those wild startup stories either don't really pan out and end up just being a waste of money, or end up a net-destructive enterprise as they monetize via piling one more brick up in our self-created surveillance state for the purpose of squeezing a few more pennies out of a "customer".
In fact, there's a great case to be made that the "boring" jobs at least tend to average being a net good for society. The "exciting" jobs have a much larger range of impact, but there's a lot more of the net-negative work in there, too.