Ill just give a quick run down on the history of the web first. Web 1.0 was the first basic visual based website display. You had things like blogs and generic information sites. You could download porn images at 5pixels a minute and in general you went to sites for reading an article or having a conversation on a forum. Then web 2.0 gave us an interactive internet, better visuals and actual application ability. As the web grew so did the speed of internet providers to the home. In web 2.0 you would see Youtube, eBay and Paypal spring up with the ability to entertain and provide commerce through the web.
I wrote an article a while ago when web 3.0 was starting to be a buzz word (https://highendlogic.blogspot.com/2016/03/web-30-and-beyond.html). In the article I detailed my thoughts on what web 3.0 would actually mean. My conclusion is that the next phase of the web was to make the internet do physical tasks. My thoughts were that this seemed like the only place that the web could grow because we already had the ability to make purchases and play games. I didnt see any other thing I would need the web to do digitally.
If web 2.0 disrupted the local shop web 3.0 ended up distrupting the need for a car. With web 3.0 you have uber and doordash make your requirement for a car obselete for any kind of in city transporation and food delivery. This is not only a great product that adds convenience for those that will pay the extra money but it actually created a entire new economy, the "Gig economy." That seems to be the key to me when we discuss defining different eras of the web. There was a real impact to peoples daily lives when they didnt have to ride the bus and instead could uber from any location. The impact on many people that we able to make an extra buck by delivering food with no friction of going through a hiring process, having to deal with a manager and the requirements to be on the job at a particular time. It was very freeing for everyone to have these types of apps available. Once covid hit many people strted to work from home. Zoom became a major player in streaming video. This further lowered the need to own a car but just enforced more that the web was not just about interacting with data remotely but instead you become part of the app yourself. Web 3.0 is an effort to decentralize civilization.
Web 4.0 will allow remote access to tasks that require more physical requirements. The remote work trend will be taken a step further. I see a time when physical tasks like truck driving or being a fastfood cashier will be done remotely and the employee will have access to mechnical structures that perform the labor on site. The mechanics will be the obsticle to overcome for this to occur but just like the Gig economy was new benefit of web 3.0 this remote work automation includes its own. This could mean major savings for companies that have insurance policies due to employees being on site. Also relistate space can be optimized requireing less space for the same task. This remote access to automated systems could also create a higher level of consistency. The military is already taken this into account with drone technology. Ill give a prediction of 2040 it really all depends on the physical machines being built but I dont expect the software to be too much of a problem.