Hearthpwn

The problem is not high-skills players at level 15-20.... the problem is that new players (or players coming back after a year break) have naturally poor (or poorer) card collection. As you rightly said... top tier netdecks are fairly autopilot for most of them... so the barrier  at lower level is not the player skill level (unfortunately) but mostly the collection level. The new Blizzard ladder system - which I like as I start close to rank 5 - does not address this.

New or returning player probably feel that - unless they pay - they will hardly be able to compete versus well tested net decks they can not afford. If a returning player did not play in 2017 and would like to re-start now... it will have a tough time to net deck as even an aggro dude pally cost about 4800 dusts, about 6500 for a Murloc pally, 6000 for secret hunter, about 4000 for secret mage or spiteful priest !!! In 2015, a top tiers aggro deck was around 1500 dusts.... the inflation is out of control at the moment.

I also agree that people will not become super creative with a "weight-based" system and will most likely keep on net decking. You are right there. However, netdecking will be more adapted to their collection ability (of newish or returning players). I do not see the reasons why all weighty meta(s) would be automatically stale and why is this is not anyway a more desirable outcome than one unique meta (stale or not) which is dominated by netdecking. It will be just a multiplication of netdecked meta but more adapted to collection access to new and returning players. 

One possible solution would be to do like in combat sport...

Instead of having only one category of deck (super heavy category) due to net-decking, a possible option will be to set "weight" categories. For example deck worth less than 500 dusts, decks from 500 to 1000 dusts, deck worth 1001 to 2000, etc.

Ideally there might be 5 categories for example.... I do not know which could be a good split as I have a large collection and am playing HS since the end of Beta.

The system will automatically find a player having a same deck category than yours while laddering (plus the usual star system). So, this system is seamless to the player. There is nothing special to do. No option to click or not. It would be just an indication by the system stating in which category your deck is.

This way, you could reach legend in the super-light category or mid-category or the super-heavy category for exemple.

It is not a perfect system. Obviously there will be more aggro on lower category and more control on higher categories (although creative people will be able to create controlish deck with less than 500 dust). Also this might split a bit the ladder. However in combat sport, it is not a big issues... yes heavy-weight are generally less moving and stronger than light-weight and that heavy-weight is more popular then super-light (due to the power level) but then it allows everyone to compete and not only the 100 kgs+ muscle fighters... which is the situation where HS ladder is now... the only difference being some fight better than others but they all look very similar (4000+ dust).

However, this will generally put the net-decking into the last category (as decks are becoming really expensive nowadays) while creative deck could be seen in lower to mid categories. It will create several meta (one by category) and thus the player experience would be more various too as many "worthless" card will be useful again.