Is mastering truly necessary these days?

While listening to some old CDs today, I pulled this one out, and it's an excellent case of someone obviously not even listening to their work.

In the 80s, when CDs were first coming out, there was a frenzy of albums that were remastered for CD. I have several CDs that had obvious flaws. One was James Gang's first album, which I actually sent back to the company as an example of putting out lousy product. They redid the CD and sent me a new one that was cleaned up. I also have Iron Butterfly's Metamorphosis which has an obvious 60cycle hum in the middle of Butterfly Bleu which lasts for a some time during a particularly quiet section. That was also redone and the new version is fine.

The most glaring example of how bad things were was Steppenwolf's first album. Imagine paying $12 or $14 for a CD and hearing the tape ramp up to speed at the beginning of songs! I still have both the good and bad copies, the only way to tell the difference is to look at the identifier codes on the inter ring of the disk. The bad one has the MCA number and LAL 74, the other has much more information. Everything else, packaging, numbering and labeling is exactly the same. How such a transfer would have made it all the way through mastering, pressing and shipping to store shelves without anyone even noticing is beyond belief.

Here's the start of a couple of the songs. First the proper master, then the botched one.

View attachment 136526

Fun days, eh?
It actually makes for a fun effect! At some point I'll try to (intentionally) apply that effect to a track.
This is the Metamorphosis track I mentioned. You could almost understand how this would get under the radar, as it's in the last 5 minutes of a full album and seems to disappear after about 20 seconds, not glaringly in the initial 2 seconds of multiple songs.

View attachment Metamorphosis Botched.mp3

There was also a Jefferson Airplane CD that I remember had ticks and pops because it had been mastered from a copy of the record. In those days, you didn't have the type of computer processing where you could easily edit a click in a few seconds. There were a few click and pop filters available, but you could also hear the speed variations from the record.
I'm not technically good on recording, but I've been doing it for 55 years or so. I read tons of books about music, bands, producers etc. etc. What I do know for sure, even speaking about well known engineers, producers etc. (meanings have changed over the years), in the end they all hear sound different, apply different techniques, and end up with a different final product (or sound). Some of the biggest names in the industry hate others final sound on specific recordings. So,bottom line, regardless of who does the matters immensely.
I think mastering is essential. Even if you master with an AI platform, you are still in effect the final engineer. So ... You can be the final person, or you can get a second set of professional ears.

This is my experience mixing large format concerts, studio bands, self produced music, and live broadcast ... More ears are good! And professional ears are worth their weight in gold.
Now we don’t have absolute requirements for the medium, for example, vinyl pressings, what exactly would a proper, professional mastering engineer do? Change what you have done? They alter your dynamics, they alter the spectral content and they change the level. If your recording is supposed to be say EDM, or metal, or some other very defined ‘club’ your music fits, membership wise, then they can fix faults. If there are no faults, they’re changing your mix, to their preference. I can understand that some music is poorly put together and needs an expert to repair. Some people produce music and put it on here for us to listen to, and their sound is consistant, and nice. They’re happy with it. They made good choices. Sometimes, not choices I would have made, but it is their choices that make it ‘them’. What benefit would paying a 3rd party bring? Something different? They might hate it.

For most people who now self release, would a mastered product result in more streams or downloads? If yours was sh*t originally, yes, for certain. For good stuff, I suspect not at all.
Excellent points. Much of the end result is a matter of taste. I've heard many rock bands say that they dislike the sound of their album due to the fact that they had no control of the final output. As a home recordist I do and I like my mixes and final sound. Could it be better? I'm sure it could if in the hands of the right ME but I think I'm in the ballpark. One problem that I have is that things sound different to me on different days. I wonder how ME's deal with that?