I have seen virtually any antivirus or security suite you can
name either praised to the high heavens or called almost
completely useless. It really depends on who's doing the
reviewing and the metrics they're using.
As has been said here, and elsewhere, antivirus programs are
not and should not be considered your first line of defense
against infection. Your own browsing habits play a far, far
greater role in that. Good browsing hygiene will keep you quite
safe, if not 100% so.
If you have not been infected nor had whatever antivirus or
security program you've been using report anything being
quarantined in a very long time you can be reasonably certain
that your browsing habits are OK. If you're constantly infected
or have things quarantined without actually having been infected
it would be very wise to start looking at precisely when, how,
and why this is happening. Most infections are the direct
result of user action, not some backdoor entry.
Windows Defender has proven more than adequate for more users
on more machines than I can count at this point in my career.
Nothing is perfect, some competitors may be better, but Windows
Defender is not even close to "junk".
This thread entitled, Windows Defender as an integral part of
Windows 10, which just started yesterday on
bleepingcomputer.com's Windows 10 Support Forum, is worth
reading [disclaimer: I've got two posts in that thread so far,
but that's not why I think it's worth looking at].
Here is a test to find out whether your mission
in life is complete. If you’re alive, it isn’t.