Depending on the model, an Intel Mac is one that had lots of competition for RAM & SSD. So instead of paying 3-5X retail pricing for Apple upgrades, one could buy the base Mac and then load it up at any time with much more internal RAM and storage for relatively dirt cheap. There was a time when Apple made this very easy. But as Apple evolved into AAPL, the pursuit of harvesting every possible nickel made some of this increasingly difficult to impossible with many Macs. The latest move forces all RAM & SSD to be purchased from only a single seller- no competition at all- resulting in 3-5X relative pricing for the same amount of RAM or SSD in PC-land.
Similarly, if RAM or Storage went bad in Intel Macs, some models could facilitate replacing the broken part and continuing to use your Mac. Now, when anything at all conks in a Silicon Mac, you throw the whole thing out and buy another.
Intel Macs could also run full Windows instead of emulated ARM Windows (which is not full Windows), making it the only computer type in the world that could natively run BOTH major platforms in one case (excluding hacks). This also meant that a single computer purchase could run just about ALL of the world's software instead of only a relatively tiny subset of it. This included easy access to AAA games and various gaming platforms on the Window-only side. Those consumers who need Windows but wanted Mac could buy a Mac and get BOTH. Now we're back to if you need Windows, you have to buy a PC unless maybe ARM Windows emulation is good enough.
It generally had a focus on Power vs PPW, so it could generally get computing tasks done faster by using more power... instead of slower while sipping power. The difference in net power usage was marginal as the former would average about a single incandescent light bulb or two's power usage each month, meaning nobody saw any huge difference in an electric bill by opting for PPW over Power. But "we" sure make it sound like it's an Apples to Oranges proposition.
Like Spotify before Apple Music or Google Maps before Apple Maps or the LG 5K monitor before ASD, when Apple was embracing Intel, fans loved Intel Macs. Then when Apple abandoned them, fans turned. Suddenly, there were all these flaws that were left unspoken while Macs depended on them but then were relentlessly spoken when Apple wanted people to buy Silicon. Suddenly laps were "suffering third degree burns", fans were "sounding like jet engines", etc.
Intel cost the so-called "Intel Premium" that Silicon would alleviate, except no pass through savings seemed to appear. Instead, Apple's corporate margin fattened, from the traditional 39%-40% to now around 46%-47%. How long until about HALF of every dollar we pay for Apple stuff is falling into the corporate vaults instead of going directly towards the thing we are buying? Hooray for shareholders! Can consumers get a bone or two?
Intel generally offered annual hardware upgrades and Silicon offered the potential of at least the same, but it didn't work out that way for the latter, while Intel has generally continued with the old, roughly annual pace. "We" blamed that on covid & supply chain, etc and maybe that was the cause... except Intel seemed to roughly stay on the traditional pace of new generations.
Intel Macs offered the ability to connect powerful graphics cards in external boxes while Silicon offers its own graphics and only its graphics... even in Mac Pro. Because of robust competitive forces, an Intel Mac Pro could have a ton of relatively cheap, massive RAM while a Silicon Mac Pro can only max out at a RAM amount of Apple's choosing... at thoroughly exploitive pricing vs. market... as is always the case when there is only a LONE seller of anything.
In short, while I can appreciate my own Silicon Mac and use it every day, we had many great benefits with the prior platform. Silicon offers several advantages but so does Intel. Chief amoung them is Power (and Graphics Card Power) vs. PPW and integrated Apple Graphics. In general, PC will use more power to get computing done FASTER while Silicon will use much less power to get things done slower. On the flip side, the latter can have longer battery life than the typical person can use in a day, while the former can burn through its battery in as little as a few hours if the task is demanding.
We Apple people shifted from a mainstream platform with massive competitive-driven support back to a PowerPC-like silo where all key roads must lead to/through Apple Inc. As objectively as I can assess it, I don't know if the pros fully outweigh the cons unless one chooses to make the pros bigger deals while marginalizing the cons. The vast majority of the world happily runs on PC platforms. Our little bubble now happily runs on Silicon... at a steep relative premium.