I am really just starting out, and I bough GoSky 10 x 42 binoculars which are very good, but they do not give as good magnification as I had hoped.
If you're just starting out, you need to bear in mind that rarely - unless viewing park/garden birds that are very habituated to humans - will you get the kind of wonderful detailed image that you might see in TV programmes. Indeed, the views that you do get may be disappointing at first - a flash of movement, or distant small silhouettes out in a field or on a mudflat. That's just part of the pastime.
You've noted that 8x and 10x binoculars are very often the choice of even the most experienced birders, and the folks above have told you why: wider field of view, greater steadiness, normally brighter than higher mag for the same size, etc. (Admittedly, often the more experienced birder is looking for "field marks" (distinguishing features) to tell him/her what species he's looking at, rather than trying to obtain the best possible view of a bird.) Your 10x42 is a classic birding format. So rather than get sucked into spending lots of money on "upgrades", it's worth thinking about things like:
- getting a feel for the range of your binoculars (at which point birds become too small) and focus on birds within that range. It's actually not unlike shooting - every firearm has an effective range and you wouldn't normally attempt a shot at targets beyond that.
- improving your fieldcraft - learning when birds are most active, how to approach them (using cover, hides etc).
- visiting locations where birds aren't too far away eg - wooded areas, parks, etc., and
- enjoying those birds that you can easily see. If you're a beginner (or even if you're not) there is a lot of pleasure to be gained from looking at even the more common birds; you'll learn how to find them and what they are (size/shape/flight), so that when you see something unusual it stands out; and you might see something unusual even in a city park.
With time and experience you'll get better views and recalibrate your expectations. And if you don't find the pastime as satisfying as you'd hoped, there's absolutely nothing wrong in that.