'What effect population had on that is harder to say but I don't think that we can seperate the technological and organization growth which made it possible from the change in population if we were to going to play "what if?"'
I do. In the US we are actually poorer than in the 50's and 60's. During those times unskilled workers owned cars and homes, products were manufactured out of more expensive but far more durable materials. The only real constant coins in the world are labor and raw materials. While that same worker might have more cans of soda in your fridge those cans are less durable, contain cheaper and fewer raw materials, and represent less labor expended to serve you. You might say, what do I care, I have more beverages! Well, you should care because that worker hasn't gained the value of those raw materials and labor somewhere else. Even within the United States the labor pool has nearly doubled with the addition of women to the workforce but the household hasn't increased the total value of raw resources and labor it controls where it should have doubled. Technology and process would have improved without globalization. For the most part the rest of the world is really riding on the tails of truely revolution technology invented in the US and Western Europe and that technology was developed before globalization.
People have been duped, they are buying cheap disposable, breakable goods, with planned obsolescence to distract them from how little value they have by showing them the quantity of "stuff" they have. An inexpensive safety razor carries most of it's cost in its raw materials (therefore will not drop in value), can be used for less than $2/yr in consumables, provides fewer cuts/razor burn and provides a closer shave vs disposables. It only takes 2-3 shaves to get used to one. Even a fairly inexpensive one is of such high quality they can passed down generations. Disposables cost hundreds a year, they are so cheap that new ones pass the holes used to save plastic off as stylizing, fake innovations are created to make old models obsolete and custom interfaces for replacement blades are used so they can phase out old blades and force people to buy new bases before even that cheap crap has a chance to break.
Mowers, gas and electric mowers don't do the job any faster than push mowers, again there isn't much material of value in them. Your fancy electric mower will break in 2yrs and doesn't do a better or faster job than an old push mower that will last forever with occasional need for oil and blade sharpening. Modernized these would be carbon fiber, use dry lubricant, possibly have rigid blades that don't need sharpened with a few flexible joints to allow for deflecting on hard objects, they would be so much lighter they'd need a strategic weight which would double as a flywheel to store mechanical energy.
Who is going to make and sell them? Nobody. It isn't worthwhile for the rich to invest in goods that are worth something and last forever unless the price is just as high as it would be for those cheap throw away goods. And if they did that people would realize they can't actually afford the modern day equivalent to grandpas old push mower.