The phrase "activity has become a" is correct and usable in written English.
It can be used when discussing a change in the status or nature of an activity, often implying that it has evolved or transformed into something else.
Example: "In recent years, physical fitness activity has become a central part of many people's daily routines."
Alternatives: "activity has turned into a" or "activity has evolved into a".
What began as an extracurricular activity has become a career, as more people have discovered the sneaky power of Crutchfield's short songs, which aren't nearly as sketchy as they first seem.
WASHINGTON — The Treasury Department has imposed sanctions on Japan's biggest yakuza group, an organized-crime syndicate that operates with relative impunity there and whose far-ranging criminal activity has become a significant concern in Washington.
Inhibition of HDACs activity has become a promising therapeutic strategy in clinical practice to reverse the abnormal epigenetic states of cancer and other diseases.
The transfer of scientific and technological know-how into valuable economic activity has become a high priority on many policy agendas.
Aβ is widely believed to have a causative role in Alzheimer's disease pathogenesis, and therefore modulation of γ-secretase activity has become a therapeutic goal.
The promotion of physical activity has become a key global public health objective [ 2].
Instead of a throw of the dice, economic activity has become an intense interchange among companies, employees, suppliers, customers, owners, borrowers, lenders and financiers.
What began as a one-time jolt in 2008, an unprecedented effort to revive economic activity, has become an uncomfortable status quo, an enduring reality in which savers are punished and borrowers rewarded by a permafrost of low interest rates.
Therefore, modulation of inflammasome activity has become an important therapeutic approach.
Cyber activity has become an essential part of the general public's everyday life.
Inhibiting glycogen synthase kinase-3 (GSK-3) activity has become an attractive approach for treatment of neurodegenerative and psychiatric disorders.
