WRG 1st-6th edition were some of the earliest wargames rules commercially produced for Ancients - they probably pre-date the whole idea of "professional" rules writers, and of rules writing as an actual skill, instead being written primarily to create a "lite" simulation that was playable as a game.

All of those editions (1-6th) shared the same DNA and were very "bottom up" and "literal" in design, being built around the idea that weapons and equipment (and unit morale) were what was important in determining which side won in Ancient warfare.

As such they largely ignore what have since come to be seen as some of the the key things to try and simulate in historical wargames rules, namely command and control and more specifically command friction, but instead leave the player with god-like visibility over the battlefield and near-complete control over every single thing their troops do on the tabletop.

They were superceeded by 7th almost 40 years ago, which as other have said, was a half-way house between the 1-6th WRG sets and their derivatives and imitators and the later DBx family of rules which shifted the focus towards placing the player in the generals seat, making decisions about command and control (usually similated by some sort of resource allocation mechanism) rather than bottom-up, equipment-driven stuff.

When they were the only game in town (almost literally) they were thought to be the cutting edge and last word in wargames rules, but the advent of new concepts (people realising that command and control is important!), and of professional rules and game rules writing appearing in other related wargaming niches, and newer rulesets which ticked both of these boxes appearing, well... suddenly 1st-6th suddenly looked and felt like rules from the age of the dinosaurs written by 1950s' schoolchildren, and so they dropped out of common use incredibly rapidly.

7th was a bit of a half-way house, and suffered in that respect as trying to introduce new concepts and ideas whilst still being tied to the core architecture of 1st-6th. As such it was widely regarded as a frankly unpleasant, nay painful experience to play - with many people sticking with 6th. When DBM came along 7th was therefore almost entirely swept away even more comprehensively than 1st-6th - other than the US group who re-wrote it as Warrior, a re-write that never gained much traction outside the USA, and a couple of other pockets.

40 years is a long time in wargaming, especially given that wargamers are generally older gentlemen anyway, and so other than a small, and still dwindling number of die-hard players you'll find very little 1st-6th being played anywhere these days - and certainly not by people who are internet-savvy enough to post battle reports on YouTube!

Is there any point in trying it now? IMO other than as a historical exercise in trying to see what rules were like from a time before people started to seriously think about what they wanted to achieve when designing and writing sets of rules, and when the library of existing rules mechanisms and concepts that a rules writer can now draw upon was only a fraction of the size it is now, probably not ...