Q: "Is it worth putting Google Adverts on my site to make money?"
A: "It depends".
There are generally three components to [sic]"earning money from adverts" on any website; 1) the amount of traffic the site gets; 2) the number of adverts clicked; and 3) the amount earned per-click.
It's important to understand that having a lot of traffic does not in of itself automatically mean earnings from advert placement is exponential, i.e. having "lots of traffic equals loads of money", whilst it can be considered a very general rule of thumb, is also an assumption because 1), it's not possible to 'force' visitors to click Adverts (Ed. it is but see the points below), and 2) the amount of revenue generated by said click activity is typically not under the control of the site owner (this assumes the use of a third party service like Google Adverts). This presents a bit of a conundrum because whilst a site owner pursues the traffic needed to remain viable the flip side is not an automatic grant of Ad revenue.
"But what about all these articles online which say you can earn thousands putting Google Adverts on a site?" Well... technically it is possible, but (there's always a "but") it depends heavily on the presence of the three points above; high traffic, high number clicks, and high earnings per click. Unfortunately these so called 'marketing articles' are more likely to mislead the Reader by pre supposing or presenting an biased picture of 'possibilities' rather than examples of abject reality, which are in fact typically very, very different (articles on "internet marketing" are not about providing the Reader with quality information but rather farming traffic for, yep, Advert clicks). For example. Reading much of the aforementioned material the typical site owner could be forgiven for the mistaken thinking that adverts typically pull in $1 or $2+ per click. Not bad the budding marketeer might think to themselves. Except... for 'common' websites, per-click revenues are closer to $0.10 cents and more often $0.01 cents a click - a vast majority of revenue generated from Ads is in this lower revenue-range, so to make the touted "thousands" from such low income per-click events, websites would require hundreds-of-thousand or millions of page views/visitors a day or week, never mind a month or year.
In addition to the above site owners have to be mindful of addressing the Visitors perception of the site when adverts are placed everywhere. Granted some adverts may be acceptable contextually, but there is a line, the other side of which is spamming every available bit of 'white-space', forced placement between comments and forum posts, page stalling, pop-ups/unders and so on, all of which negatively impact the 'reputation' or 'street cred' of a website irrespective as to its inherent value as an information or service source; visitors begin/see the site as being there solely to generate revenue from their input. This is a BIG turn-off generally, being one of the major major reason why people stop visiting (notwithstanding lack of site activity of course).
If so, the 'trick' then, if it can be called that, is to place adverts such that they don't spam the appearance of the page nor interrupt the users ability to navigate the site unhindered. Some sites do this regardless but have such a near monopoly control over their follows that they can afford to 'tunnel' users in this way. Being a "small fish in a big pond" with a fraction of the traffic, the lowly site owner can't afford to play such games with users so the better approach is to be slightly more conservative and perhaps experiment with placements to see what happens. Don't spam however, that desensitises the user making them 'blind' to Advert placement on a page which defeats their purpose. The key to remember is that your game, portfolio or content website is about engaging an audience, not distracting or pushing them around for the sake of a (pittance) payout.