These types of threads come up a lot on the internet.
Cricket and baseball are completely different sports. They look a lot more similar than they are. I'll make some comparisons that hopefully help you see that they share very few similarities.
We can compare some aspects
General Batting:
-Cricketers have bats with a flat face that allows them to place the ball more accurately when they hit it. Placement of the ball is an extremely important aspect of cricket, and they have a full 360 degree field to make use of.
-Baseball players have rounded bats that are more aerodynamic and designed to impart the maximum possible amount of force on the ball. Hitting with power is more important than anything for baseball batters.
Facing bowlers/pitchers:
-Baseball: The location of the ball in baseball is more predictable and if it's outside the (small) strikezone, thats a big advantage to the (almost always). The difficulty in hitting the ball in baseball is the basically the speed (look up blindspot)
-Cricketers face balls that can be bouncing over their head or aimed at their toes. The ball can go behind their back or a yard in front of them. They do have the blindspot as in baseball, however that only generally occurs before the ball bounces. In cricket the batter sees the bowler release the ball, then looks where they think the ball will bounce to pick it up again before hitting it (for a fast bowler anyway).
Bowling:
-Cricket has a variety of bowling styles spin, swing, fast, medium, seamers. Each of these bowlers has variations fast ball/slow ball/curveball/cutter/googly/stock delivery, these variations also go with variations in where the ball is pitched (yorker/full/short/bouncer/full toss). A spin bowler and a fast bowler are wildly different but can both be as useful as each other.
-Baseball pitchers all fit into the "fast bowler" type from cricket. Then they have their variations fast ball/curveball/change up/knuckleball.
-The action of cricket bowlers and baseball pitchers are completely different. Cricket bowlers are not allowed to bend their arm and must generate some additional speed by using a runup, baseball pitchers can use a bent elbow to apply maximum velocity to the ball. Although there is significant technique involved for pitchers, I think it would be easier for a cricket bowler to transition to being a pitcher than the other way around.
Fielding:
-Baseball is more complex because of the way you can get outs from batters trying to steal a base and 2nd phase play.
-In cricket, the ball is "dead" between pitches so the players can not try to steal a run and there is no such thing as a 2nd phase play.
-Otherwise fielding in baseball is significantly easier. There is generally less ground to cover, you can catch with gloves, they can touch the walls of the stadium while catching with no penalty, they require less reflexes compared with cricket slips & silly mid on/silly point positions.
I think very few world class players could convert between the two sports successfully and doing so would require great dedication and cost them a lot financially.
As for players transitioning between sports:
I doubt any bowlers/pitchers could transition between the two sports. For batters, The biggest issue for baseball players would be technique, it would take years for a professional baseball player to be able to play spin or bat two balls in a row where one is crashing into their toes and the next is coming straight for their head. So that pretty much rules out that transition. All that is really left is a cricket batter transitioning to baseball which would be difficult, but wouldn't surprise me.
I actually think baseball has more complex rules and is therefore more difficult to watch and understand, whereas cricket is more complex to play because of the technique involved.
I like both sports but I wish people stopped trying to say one is better than the other and by extension all athletes in one would dominate in the other if given some training. They are completely different sports and this comparison would be like saying all MLB players could play soccer at the highest level because of .