There are multiple references in the Torah to the situation of Jewry in Diaspora, regarding the Curses God is to send upon us and otherwise. Those discussions put a lot of focus on our Serving Gods of Wood and Stone. We know however, that the inclination for Idol-worship was more or less destroyed before the destruction of the Second B"H, and obviously Idol Worship does not play a central role in our sins of today. What the was the Torah so busy with in predicting? Was it referring to Galus Bavel? Or was it simply a non-essential example of ways in which Jews may rebel against God in the future?
According to this answer by ray, the Yeitzer Hara of idolatory wasn't exactly destroyed, but transformed. How this modifies the halachic considerations of idol worship is another discussion, but the principles carry forward.
Let's get to the root of what idolatry is and see if it can still apply post the "pagan" days of worshiping personified deities.
(Devarim 5:7,9) "Thou shalt have no other gods before me….Do not bow down to them and do not worship them, for I, the Lord thy God, am a jealous God".
Having another "god" before Him means we give some or all of our service that should be for Hashem to something else, which includes faith, trust, devotion and loyalty, to a god who cannot save, אל־אל לא יושיע (Yishaya 45:20). This is most keenly felt in the term "I am a jealous God". This type of jealousy, kinna, is akin to a husband who suspects his wife of cheating on him (see Bamidbar 5:12,14). The sense of repugnance at betrayal is a theme.
Putting our faith and trust in a "false god" is particularly egregious, and Hashem's criticism of "you worship the work of your hands" rings loud - why are you worshipping something that is inferior to you? Hashem has placed us in a world with angels above us, and animals below us, and gives us the ability to rise or fall towards either with our unique free will. The only way to rise is to worship that which is greater than us, and that is only Hashem. When we are devoted and loyal to Hashem, we adore Him (literally worship - we say He's absolutely perfect in every way!), and do our best to strive to emulate Him, then we are doing what we were created to do, and going in the direction He needs us to go.
As Rambam lays out in the first perek of Hilchot Avodah Zara, by creating a god that cannot speak or have a will, and dedicating oneself to it, one has to build lie upon lie in order to maintain that. Whether it be a literal idol made by ones hands, or anything man made that we put our faith into, it's all the same. We end up really just worshiping our own opinion, and more and more urgently defending it with rationalization and lie after lie.
Another point I've heard: It's not even worship. The worship is also false. It's more recklessness. Putting one's faith into something that cannot save is not real worship.
So can this apply today? In the way it's been explained here, yes of course - see the sources in ray's answer, or this set of shiurim for example. Study the links in Shmuel's comments in the OP. It is just as poignant and dangerous as ever - perhaps more so because we find it much harder to spot! One can put one's trust and faith in one's money, in one's deservedness and entitlement, in a foreign ideology, in a government or even a celebrity. We can feel like that's what we want to dedicate our strength to, put our trust that this is how the world will be saved, and identify ourselves as one of its adherents and followers.
It's worth noting that it is often discussed that all our idols have let us down. We are getting desperate and it seems that many people are now saying nothing can be trusted, so they only trust themselves. "Whatever my opinion is, is right and the only thing I can trust". Worshipping the self is the quintessential form of idolatry. Even that idol either needs to be relinquished, or it needs to be smashed.
It's scary, if I can't trust myself, then who can I trust? If I am not to dedicate my heart, my mind, my deeds, my words, my thoughts, my body, my soul to myself, then who should I dedicate these to? The answer is the same answer as it's always been: trust Hashem, dedicate oneself b'mesirat nefesh to Hashem. He gave us a Torah and it tells us what to do: focus on the 613 mitzvot and all halacha with complete abandon; one will then be guaranteed to be going only upwards, doing the only right thing to do, fulfilling one's true purpose, and fixing the whole world. One will be blessed and protected and be given a portion of Hashem Himself, and indeed be connecting to one's true self, free of all falsehood and lie, all desperation and trap.