Why don't advertising agencies advertise themselves anymore?

Here's a great collection of classic agency advertising.

Ad agencies used to take great pride in creating great ads for themselves, communicating exactly what they stood for, a point of view, a point of difference and what to expect from them if you were a client.

It got me thinking, why don't ad agencies advertise themselves any more?

Isn't it a little odd that today no, or at least very few agencies seem to do there own advertising?

Why is this? Is it because they are unwilling to stand for something, or that they don't want to stand out as being unique, or difficult to work with? Or because they don't want to seem to be back slapping and overly confident?

Or have times simply changed and today the work that an agency produces for their clients is the best form of advertising, and word of mouth, and PR so there is simply no need to advertise?

Who knows. It's a shame though.

Agencies today seem to produce generic, brand films and showreels, and most agency social content is pretty bland and extremely similar to every other agency. It's very inward looking, surely it must be very boring for clients? Stats, opinions, insights, webinars etc are all well and good up to a point. Are agencies today just wanting to appeal to every possible client, and so are nervous about standing out and having an opinion?

Shouldn't agencies demonstrate how unique they are, and how good they are at creating ads, by creating great ads for themselves. Communicating their point of difference, start a conversation, be different, standout? Show a human side, have character, and maybe a bit more fun?

It would certainly help stand out and have a clear message, after all isn't that what clients want for themselves and from their advertising agency?

What are your thoughts?