Advantages of the VirtualDelay library:

• The delay is virtual, during the delay, the code execution is continued
• We can use multiple delays sequentially in a loop.
• We can use multiple delays simultaneously and independent of each other.
• The delay time can set in micro-seconds or milli-seconds.
• No hardware timers are used
• The library is timer-rollover safe

See the article https://www.avdweb.nl/arduino/timing/virtualdelay