El Capitan, My El Capitan

I wanted to re-install El Capitan on my very old MacBook Pro. It had 2 disk partitions which I wanted to merge but couldn't do so via Disk Utility while in recovery mode. It won't start-up recovery mode via internet with Command + Option + R. 

My scouring over the world wide web ended in me having to:

• Download the dmg file from Apple.
• Run below commands in Big Sur (or any macos which has higher version than El Capitan) to create the installation media (using a 32GB flash drive):
• rm -rf /tmp/El\ Capitan
• pkgutil --expand /Volumes/Install\ OS\ X/InstallMacOSX.pkg /tmp/El\ Capitan
• diskutil eject Install\ OS\ X
• cd /tmp/El\ Capitan
• hdiutil attach InstallMacOSX.pkg/InstallESD.dmg -noverify -nobrowse -mountpoint /Volumes/esd
• sudo asr restore -source /Volumes/esd/BaseSystem.dmg -target /Volumes/MyVolume -noprompt -noverify -erase
• diskutil rename /Volumes/OS\ X\ Base\ System /Volumes/Install\ El\ Capitan
• rm /Volumes/Install\ El\ Capitan/System/Installation/Packages
• cp -rp /Volumes/esd/Packages /Volumes/Install\ El\ Capitan/System/Installation
• cp -rp /Volumes/esd/BaseSystem.chunklist /Volumes/Install\ El\ Capitan/
• cp -rp /Volumes/esd/BaseSystem.dmg /Volumes/Install\ El\ Capitan/
• hdiutil detach /Volumes/esd
• sudo bless --folder /Volumes/Install\ El\ Capitan/System/Library/CoreServices --label Install\ El\ Capitan
• cp /Volumes/Install\ El\ Capitan/Install\ OS\ X\ El\ Capitan.app/Contents/Resources/InstallAssistant.icns /Volumes/Install\ El\ Capitan/.VolumeIcon.icns
• cd "$HOME"
• rm -r /tmp/El\ Capitan
• diskutil eject /Volumes/Install\ El\ Capitan