Quartz has an infographic showing the family tress of the six largest beer companies that sell 50% of the world's beer. Consolidation has been huge factor in the beer as an investment story. As anecdotal evidence of the industry's progress, AB Inbev was running ads against itself during the last World Cup.
One could spin a negative story that the industry has been growing by acquisition rather than organic growth and that tastes in major markets have been steadily shifting to wine and spirits.
The positive story is that the industry has recognized changing tastes and that consolidation is a sign of market discipline to keep margins high. Size also creates strong moats around the firms. It would be very difficult for any new entrant to take on the large incumbents in terms of: (1) brewing large volumes of beer of consistent quality; (2) mass marketing; (3) distribution to stores, bars, restaurants, stadiums, festivals, etc; and (4) entering emerging markets where beer can still be a growth story (due to some combination of rising incomes, weak local competitors, and beer as a relatively novel category).
In regards to craft beer: Often delicious. But the trend is not new, and for every successful independent, there are a host of competitors hoping to be bought out by a large multinational.
I hold a material part of my personal portfolio in beer stocks. This is primarily through Ambev, SABMiller, MolsonCoors.