Choice in Tarkov is fundamental to the game. If you've ever played some of Tell Tale studios games before they folded you'll know that choice is a significant aspect of making a game engaging. Unlike in Tell tales games where the story guides the player to fixed events Tarkov gives the player a lot more freedom within it's system to make choices. The way that Tarkov is designed is to encourage players to make meaningful choices.
Beyond being shot at, game instability, and spawn location players are completely in control of their experience. From choice of gear, to the raid location, and all actions taken in raid, these are all decision points for the player. During a fight if someone peeks a corner when they know someone is aiming right where their skull will be that is a choice. If a player wants to bring in a load out that weighs 70 lbs they can do so. Each decision has consequences though.
The peek as described above has the consequence that will most likely be getting a bullet through the brain. If someone brings in 70 lbs of gear to mow down enemies and tank some bullets they won't be able to carry much more. Determining risk and reward for everything in Tarkov is part of the game
If a player chooses to play alone then they are choosing to risk their gear and being vulnerable to things that they otherwise would not be with a group. The reward is that every piece of loot they scrounge out of a raid is theirs to keep. If a player loads in with a group the reward is that they have more security and a higher survival rate. The risk is that the group is collectively louder and they might not come out with enough loot to pay for the cost of ammunition.
Being a lone wolf means that if a player chooses to take a fight with a 4 man squad they are probably going to die. If they come in with a gen 4 assault and a FAL with three 50 round drum mags they won't move very fast if their loaded down with 2 more guns and an armored rig stuffed with full magazines. Tarkov is forces each player to make these types of choices because a single person in real life with combat experience can only handle so much.
There are many decisions a player can make. When a player is getting ready for a solo raid that player can choose to run a smaller magazines or a lighter gun in the same caliber to get the same result. Maybe that player chooses to run a killa armor instead of a gen 4 to save on the weight cost and get the same armor level.
These changes (weight, roles, etc) shouldn't dissuade anyone from running anything. It just means that playing solo will become more appropriately difficult. The meta may shift towards solos and groups of 2 running lighter weight gear and being much faster than giga-chads in groups of 4 or 5. There are downsides to each and the game is changing to reflect this. Solos aren't getting nerfed, they are just getting put on a realistic playing field. Playing solo has always meant being stealthy, now it will mean being fast and lightweight too.
This game is, at it's core, meant to be difficult. Making something as realistic as possible given that the limitation of being a video game won't make it 1-to-1 scaled with real life is a difficult ask but the team at battlestate are getting closer with each update. This game won't hold anyone's hand. Each player needs to find their balance with this game. If that means some people don't want to keep playing then that's their choice. Those who desire a game as complex and difficult as Tarkov will find their way to success and enjoyment, regardless of change.
TL;DR – Tarkov is a game of making decisions. Understanding that everything a player does in game affects their outcomes is fundamental to being successful.