I shoot 4x5, and use both strobe and flashbulbs.
One reason to use flashbulbs is because they result in a different look than strobe. This may have to do with how black and white film reacts to flash bulbs vs. strobe. Flash bulbs give a longer duration blast of light than strobe, and with a broader spectrum of wavelengths of light. Film reacts differently with creamier highlights and improved shadow detail compared to strobe.
Flashbulbs are also light, powerful, and highly portable. They come in different output strengths, and are especially good for bounced light lighting.
Give it a try!